Category Archives: Geology

Atomic Structure, Diamonds, Geology, Minerals

The Carbon Atom

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Illustration of the carbon atom
Bohr Illustration of the Carbon Atom. Photo: Photo by dacurrier on Pixabay

Carbon Element Overview‍

If you watched Star Trek, in one episode, the Nomad, the robot that referred to humans as carbon-based lifeforms, and for good reason. Because that’s what we are! 

Virtually every organic compound on Earth contains carbon. Life as we know it would not exist without carbon. That’s because it has a unique ability to bond with itself and other elements fairly easily, due to its need to find more electrons to bond with.

Carbon is the sixth element in the periodic table with the chemical symbol C and an atomic number of six. It has two electrons in its inner shell and four electrons in its outer shell (valence shell) as shown in the Bohr illustration above.

Because the carbon atom has a natural desire to fulfill its outer shell with eight electrons or saying it another way, it needs to fill up its outer energy level, it will constantly look to bond with other atoms to obtain four more electrons. Once bonded, the atom’s outer shell is fully stable. Carbon atoms can form bonds with other carbon atoms, but they can also form bonds with almost all other elements. 

Carbon can exist in multiple different forms known as allotropes: graphite, diamond, and others. It’s also a non-metal, but one of the most important elements on earth. Carbon atoms have many uses, from making steel to fueling cars.

This article explores almost everything you wanted to know about carbon atoms and their various forms.

Types (Allotropes) of Carbon Molecules

Graphite

Graphite showing a pencil
Image by Gino Crescoli from Pixabay

Graphite is an allotrope of carbon. It’s a black and soft mineral that is commonly found in nature in the form of pencils. Although graphite is often treated as a mineral, it’s more commonly considered a form of carbon. Graphite is very soft and can be easily compressed into a very thin sheet.

Graphite is made of layered sheets of carbon atoms that form stacks known as graphene. Each layer is made of carbon atoms arranged in a hexagonal pattern with strong covalent bonds. These layers are held together by weak intermolecular forces that are easily broken by heat. That’s why pencils can be erased by rubbing graphite and paper together!

The Diamond

The diamond is another allotrope of carbon. The only difference between the two is that diamonds are made of carbon atoms arranged in a cubic pattern. This makes diamonds a hard and rigid substance. 

Diamonds are also made of graphene sheets that are held together by strong covalent bonds. These properties make this mineral extremely valuable, but they’re also highly limited in supply. That’s why they’re one of the most expensive materials on earth. 

It’s estimated that only 0.1% of the carbon that enters the earth’s surface is converted into a diamond. This is large because diamonds are formed at very high pressures beneath the earth. 

When carbon deposits are subjected to a combination of very high temperatures and pressure, they can change to diamonds. It may take a long time before the carbon is changed into a diamond, but it will change. It all depends upon the temperature and amount of pressure that is put on it. We can’t find a better demonstration than when Superman crushed coal (a product of carbon) simulating the creation of a diamond. 

Carbon Bonds

The covalent bonds that can form carbon can result in many different types of molecules. Carbon can form thousands of bonds with other elements. This is why carbon has so many uses in the world.

Fullerenes

Fullerenes are carbon molecules that are composed of many rings of carbon. They were accidentally discovered in 1985 by two scientists who were studying carbon soot. The discovery was so exciting that the scientists won a Nobel Prize for their discovery!

C 60 – the most common carbon molecule – has 60 carbon atoms arranged in a spherical pattern. This sphere can be thought of as a football because the name “fullerene” comes from two English words: football and carbon.

C 60 is known as a buckyball and can be used as a tool for scientists. Yes, that’s what it’s called. Buckyballs are carbon atoms that are bonded to three other carbon atoms. Scientists can use buckyballs to study the structure of other molecules.

Why is There So Much Carbon in the World?

Carbon is the fourth most abundant element in the universe. Carbon is created in the interiors of stars and then released into the universe when those stars expire. It is present in the earth’s crust in the form of minerals and organic compounds. C 60, the largest buckyball, is only possible at a pressure of 100 gigapascals – the type of pressure that’s found inside giant planets. (A pascal is a unit of pressure. Gigapasclal is that unit of pressure x 1 billion).

Diatomic Carbon

Diatomic carbon is the simplest form of carbon. It contains two carbon atoms with one double bond between the atoms. A double bond is where an atom shares its valence electrons with two other atoms, in contrast to a covalent bond created by lighting and oxygen in the air, but it is usually destroyed by other compounds in the atmosphere.

This is important because diatomic carbon is a greenhouse gas. Carbon atoms are released into the atmosphere when plants are burned. These atoms are then oxidized by the other compounds in the air to create more diatomic carbon. Diatomic carbon is one of the most important greenhouse gases in the atmosphere. This is precisely why it was released in the first place!

Conclusion

Carbon is the element that forms the molecules for all known forms of life on earth. It’s the only element that can form molecules with a ratio of electrons to protons that’s necessary for biology.

Carbon is not a metal. Metals are largely defined by their electrical conductivity. Carbon is a non-metal and does not conduct an electrical current.

Illustration of an extraterrestrial
iStock

Carbon is also very common in the universe and can form multiple different types of bonds with other elements, so when Noman called humans carbon-based life forms, because of its abundance in the universe, maybe he met other carbon life forms in the galaxy we just don’t know about yet!

 

Astromony, Geology

What Are Moon Rocks Made of?

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The Man in the Moon or Is It the Earth in the Moon?

What would Dwayne Johnson become if he landed on the moon?
A Moon Rock. OK, a little bit corny but this puts us right where we want to be. A discussion about moon rocks. 

The Apollo 11 crew: Armstrong, Michael Collins, and Buzz Aldrin.
The Apollo 11 crew: Armstrong, Michael Collins, and Buzz Aldrin. Wikipedia/Nasa

We’ve long wanted to know what the moon is made of and thanks to Neil Armstrong, Buzz Aldren, and the 10 additional heroes that followed them, we now know not only the material composition of the moon but the history of this satellite which in turn gives us a better idea of how the earth and moon were born.

So What is the Moon Made of?

When scientists investigated the moon’s composition, they found that it is made up of minerals that originally came from the Earth.  This means that the rocks on the moon are just like any other rocks on Earth.

Moon Rock
Goodwill Moon Rock

Above is a Good Will moon rock. Just one of the pieces that were distributed by President Richard Nixon to all the countries of the world. Let’s take a closer look at what elements actually exist on the moon.

    • Iron, which ranges from 5% to 40%. Earth has an abundance of this element as well.
    • Oxygen is another common element found in both lunar and terrestrial rocks. It ranges from 2% to 20%.
    • Silicon is also present in both types of rocks, but it only makes up about 0.2% to 1% of them each.

These elements are separated into different layers in the moon’s crust. The lighter materials, like silicon and aluminum, are near the surface because they are less dense than other elements. Iron is located at a greater depth because it is heavier than any other material on or around the moon.

What Were the Thoughts Before the Moon Landings?

The reason it took so long for us to figure out what the moon is made of is that no one was able to analyze it closely before humans landed on its surface for observation.

What Did Previous Research Say About the Composition of the Moon?

Previously, scientists believed that the moon had some similarities to the Earth’s mantle. They thought that it contained mostly potassium and some iron-nickel, which is common in Earth materials like the crust. But this new research found that the moon is actually made up of rocks like granite and basalt (molten rock).

Additionally, the lunar crust was primarily made up of feldspar minerals. This theory has since been disproved by new research methods that show that these minerals don’t exist in enough quantities to account for all of the moon’s composition.

These theories came from data collected by Apollo missions in 1968 and 1969. This new data comes from an analysis of lunar samples that were gathered by NASA’s Lunar Prospector mission in 1998.

The researchers think that this difference in findings can be explained by how scientists analyzed these samples. The Apollo missions were looking for a type of radiation called K-Ar, which releases a lot of potassium when a rock gets heated to a certain temperature.

To find this radiation, they used a process called “wet chemistry”, which involves putting gases into molten rock until they bubble out. The Lunar Prospector mission used a more precise technique called “multicollector inductively coupled plasma-mass spectrometry” to measure all sorts of elements to get an idea about it’s composition.

1986 to 1992 Moon Analysis

NASAs Lunar Prospector
Lunar Prospector. Wikipedia-NASA

In 1986, NASA launched the unmanned probe Lunar Prospector. Over its two-year mission it made detailed measurements of the lunar surface. The probe was able to collect data that would help scientists understand more about our Earth’s neighboring planet.

Lunar Prospector had three main objectives:

    • Search for water and other minerals on the lunar surface;
    • Determine whether or not there is water in ice form at or near the lunar poles; and 
    • Investigate if there was any evidence that meteorites from Mars may have come from another location besides Mars.

For two years, this probe collected data and sent information back to Earth, which helped scientists understand what materials make up our moon. However, in 1998, US lawmakers canceled funding for the project due to budget limitations.

At the Beginning

The moon was formed when a planet-sized object hit the Earth, sending fragments into orbit. These fragments eventually assembled to create the moon via gravity.

It took scientists a long time to figure out what materials make up the moon because it’s difficult to analyze such a small and far away object. Scientists found that the minerals on the lunar surface are younger than we previously thought, and they came from Earth itself.

Scientists analyzed samples of lunar rocks and looked at their chemical composition. They found that these rocks were much like those in Earth’s mantle and oceanic crust: they had the same chemical composition as materials found in Earth’s crust and mantle.

In other words, scientists figured out that all of the material for this celestial body came from Earth itself. This answer is surprising because until now people assumed that everything on earth had come from outer space!

Conclusion

There may still be some mysteries about the moon that scientists haven’t yet solved, but when it comes to its composition, there’s not too much left up in the air or vacuum to be more precise. 

We’re always striving to answer our questions about space and with this information, we can now say with certainty what the materials are that make up our nearest neighbor.

Plans are now being made for additional manned trips to the moon along with the building of lunar camps for humans to live in. This is only the beginning. Stay tuned!

Geology

What are Bridge Bearings?

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The Coefficients of Steel and Concrete

A concrete column
Concrete column supporting the highway above. Photo by SS

In our previous articles, we discussed the mineral components of steel and concrete. In this article, we will dwell further into the element’s composition and how they are affected when there are changes in temperature. 

All elements on our planet change in size when the temperature increases or decreases; although very minimally, but when dealing with the engineering of buildings and bridges, this change, however slight, could become catastrophic if not properly addressed and compensated for.

Such is the case for iron, steel, and concrete. They expand and compress as the temperatures increase and decrease, respectively. A good way to remember which direction they are moving is: increase = expansion and decrease = compression.

Each element has a specific temperature coefficient. Even if it is just a tiny amount, if there is not enough room for the material to ‘stretch’ (expand) or decrease (compress), it will show signs of wear, and after a time, it could break and everything above it will collapse. In this table, we can see how much materials expand or contract per degree.

For the mathematically inclined:

If 1 mile = 5280 feet, then 1 mile equates to (12 5280’) = 63360”.
1 inch of steel expands 0.00000645” for every 1 degree Fahrenheit increase in temperature; therefore, 63360” 0.00000645” = 0.408672 inches per degree.

Thus, as the weather gets warmer, steel will expand 0.408672 inches for every one degree in temperature.

Material Expansion and Compression MUST be Compensated for in Construction!

In this Pipes and Tubes Temperature Expansion table, you can see the minimal effect of stresses that are placed on certain metals; however, if not compensated for, the integrity of the elements will be compromised.

The question then is, what happens to bridges that have steel columns? If they expand and compress without freedom of movement from temperature differentials, the steel will eventually crack and can lead to a defective bridge.

Enter Bridge Bearings

The answer is bridge bearings (previously called rollers) that allow for the stresses of the steel to move in either direction.

In the photo below, a cylindrical bearing is placed between the vertical supports, called piers, that would otherwise be permanently fastened to each other. The bearings in between them allows for the bridge to expand and compress freely.

A bridge bearing
Photo by SS

In summary, the function of a bridge bearing is to transmit and distribute superstructure loads to the substructure (bridge) and permit the superstructure to undergo the necessary movements of stress, which can consist of compression, shear, and rotation, consequently preventing overstress, which would otherwise compromise the structural integrity of the bridge. 

Bridge Bearing Types

There are several types of bridge bearings utilized and are dependent upon a number of different factors, including the length of the bridge span. The oldest bridge bearing involves just two plates resting on top of each other. 

Here is a good illustration of bridge-bearing plates. It depicts quite well how the plates are stacked on top of each other, as well as the limitations placed on it, such as the guide block, which prevents the plates from sliding off. This plate scheme can be seen on many bridges, especially those that span highways and parkways.

A common form of a modern bridge bearing is the elastomeric bridge bearing, which is more common today. Besides freedom of material stress, they also extend the life of the bridges by reducing continuous wear and tear on the bridge materials. 

The Bay Bridge collapse after the 1989 7.1 magnitude Loma Prieta earthquake is a perfect example when using inadequate bearings for a structure, especially within an earthquake zone. The use of elastomeric bridge bearing should help to alleviate the engineering errors that caused this part of the road to collapse.

As you travel, you might want to locate the bearings on the bridges you drive on, and now, have a better idea of what those things are that are attached to your bridge.

 

Geology

Catastrophic Earthquakes in Haiti

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Birds eye view of Haiti
Image by David Mark from Pixabay

Haiti is one of the poorest countries in the western hemisphere, so it doesn’t take much for death and destruction to occur when a catastrophe hits. More developed nations have higher quality construction for their infrastructure which helps to curtail some of the destruction when a major event happens. 

Additionally, developed countries have well-equipped first responders and hospitals that can handle disasters such as earthquakes. Haiti does not. Suffice it to say, there will be more injuries and fatalities for countries such as Haiti than in other, more technologically advanced locations.

Earthquake History in Haiti

Earthquakes have been causing extensive destruction on this island for quite some time. Starting from the 18th century, when the capital Port-au-Prince experienced severe damage twice within 19 years, the trend continues to date. 

During this century, the island has already been devastated by an earthquake thrice, with the most recent one striking on August 14, 2021. The quake of magnitude 7.2 struck around 78 miles from Port-au-Prince, killing, injuring, and displacing thousands of people, and resulting in millions of dollars of losses. 

Let’s take a closer look and understand why Haiti is more prone to earthquakes and get a detailed insight into some of the most devastating earthquakes that have hit the island recently. 

Why are Earthquakes in Haiti a Common Occurrence?

The Earth’s crust is made of tectonic plates, and each of the plates moves in a certain position. There are seven major tectonic plates along with ten minor tectonic plates. Earthquakes occur when the tectonic plates slowly brush against each other and result in friction. When there is enough buildup of friction, the fault lines suddenly move and lead to an earthquake. 

If you look at the location of Haiti on the map, it sits near the intersection of major and minor tectonic plates, namely the North American Plate and the Caribbean plate. Moreover, multiple fault lines cut through the plates near the island of Hispaniola, a region that Haiti shares with the Dominican Republic. Unfortunately, not all tectonic plates behave the same way. The transition from sliding past each other to smashing together leads to frequent and intense earthquakes. 

Haitian family outside of their cinder block house
Haitian family outside of their cinder block house in the town of Hinche.
Photo by SS

Part of the reason is the dense population of the island. A population of more than 11 million people results in more damage to lives when natural catastrophes occur. Moreover, many of the buildings are constructed using cinder blocks, which can withstand strong winds and hurricanes, but they are not very sturdy (as compared to concrete blocks) and are prone to buckling. Not an ideal structure when an earthquake comes along.

Most Devastating Earthquakes of the 21st Century 

Now that you know why earthquakes in Haiti are devastating, let’s look at some of the most damaging ones that hit the island in this century. 

The 2010 Earthquake – Port-au-Prince 

A large-scale earthquake that measured 7.0 on the Richter’s scale hit the island on January 12, 2010. The quake hit around 15 miles southwest of Port-au-Prince, followed by two aftershocks with a magnitude of 5.9 and 5.5, respectively. The island experienced more aftershocks in the days that followed. The 2010 earthquake was the worst quake that hit the island since the 18th century. 

Communications were disrupted and led to extensive damage to life and property. The death toll for this earthquake is not known. However, it resulted in millions of casualties and hundreds and thousands of people being displaced due to the chaos. 

Initially, geologists believed that the earthquake resulted from the movement of the little Caribbean place towards the east; however, it was just an initial estimation. Later, geologists found out that it was a result of contractional deformation along the Leogane fault. Léogâne is a town is located about 19 miles west of  Port-au-Prince.

The damage that occurred due to the 2010 earthquake was fairly extensive because the origin was relatively shallow (at a depth of 8.1 miles), which increased the intensity with which the ground shook. Port-au-Prince and the surrounding areas were among the worst affected. The island that was already recovering from the infrastructural damage due to tropical hurricanes in 2008 was not equipped to deal with a disaster of this magnitude.

In addition, since Haiti is considered to be the poorest country in Western Hemisphere, it did not have the resources to properly restore its infrastructure. Hence, international organizations, including the United Nations, had to work in collaboration with the Government of Haiti to establish a plan for reconstructing the island.

The 2018 Earthquake – Port-de-Paix 

While the island was still recovering from the earthquake of 2010 and its after-effects, another major quake hit the island. This time, it was not as intense as it was in 2010. However, it hit the island with a magnitude of 5.9. It struck around 12 miles northwest of Port-de-Paix, killing around 18 people and injuring more than 180 individuals. While there was a limited loss of lives, there was extensive damage to property, including commercial and residential locations. 

The earthquake was felt in Port-au-Prince along with the neighboring Dominican Republic and is one of the strongest hits to the Caribbean nation since 2010. 

The 2021 Earthquake – Nippes, Les Cayes

An earthquake with a magnitude of 7.2 struck Haiti on August 14th, 2021. The epicenter was 6.2 miles deep, and the tremor was strongly felt approximately 91 miles west of the capital. The resulting damage was extensive. However, it was much less than what the nation experienced in 2010. According to initial estimates, more than 1.2 million people have been affected by the quake with about 2,000 people have lost their lives. There was also extensive damage to infrastructure, including schools and residential buildings. 

To date, the 2021 earthquake is considered to be the deadliest earthquake that has hit the island since 2010. 

Conclusion 

Haiti sits on the intersection between two tectonic plates, which is also a region of several fault lines. Hence, earthquakes are and may likely be a frequent occurrence on the island. The damage is always extensive because of the lack of appropriate infrastructural facilities on the island.

Geology

How Do Glaciers Form?

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The Alpine Glaciers 

Mountain or alpine glaciers are the ones that are formed on the mountainside and move downward over the mountainous slopes. It is possible for alpine glaciers to even create or deepen valleys as the accumulated ice exerts pressure over land, pushing it downwards. Alpine glaciers can be commonly found in almost all continents (except Australia). Some of the most famous alpine glaciers include Gorner Glacier in Switzerland and Furtwangler Glacier in Tanzania. 

Ice Sheets 

Unlike alpine glaciers, ice sheets are not limited to the mountainous region. Instead, they are more like a sheet of ice that spreads from the center in all directions. As the ice sheet spreads, it covers everything under the thick coat of ice, including plain areas, valleys and even mountains. Continental ice sheets are large ice sheets that cover a large area. As of now, the continental ice sheet covers most of Antarctica and Greenland.

Additionally, ice sheets covered much of Europe and North America during the Ice Age, when around 33% of the planet was covered with ice. As the climate changes, glacial ice sheets, so far cover only 10% of the land. Due to the ancient glacial ice sheets and the pressure they exerted on land, many of the landscapes on Earth exist in their present form. 

How Do Glaciers Form?

It might come as a surprise, but it all starts with a snowflake. However, it takes an incredible amount of snow to form and pile up as a glacier. Once the snow accumulates, the snowflakes, given their structure, begin to compress each other and pile up each year. When the snow accumulates year after year, it changes from fluffy and soft snowflakes into round ice pellets. With new snow coming over the buried hardened snow, the latter hardens and becomes even more compressed. Eventually, it changes into dense, grainy ice, which is known as firm. 

The process continues, and layers of firn build on top of each other. When the thickness of ice grows up to 160 feet, the firn changes from grainy ice into a solid mass, which is how a glacier is formed. However, it doesn’t happen overnight. This process of formation takes over a hundred years, which is minuscule compared to that age of the earth (4.5 billion years). 

Because of its weight, the solid mass of ice is so heavy that it begins to move. Moreover, the glacier exerts pressure on the underlying firn and snow due to its weight, which eventually melts without any temperature change. 

In the case of alpine glaciers, gravity plays an important role. However, some glaciers do not flow down the entire length of the mountain. Instead, the ice falls from the hanging glaciers to the larger collection of ice in the valley below. Avalanches and ice falls are common occurrences for alpine glaciers. 

On the other hand, the ice sheet spreads out differently. The giant mass of ice spreads in all directions and covers everything that comes in its path. However, the speed at which the glacier spreads varies because different parts move at different speeds. And it is because of the difference between the speeds at which the glacier spreads, there is tension within the upper part of the ice mass and consequently, you find cracks known as crevasses on top of the glacier. 

Crevasses can be particularly dangerous for mountaineers as they can open up and be quite deep. Another formation that you can find within a glacier is a deep, almost vertical pipeline known as moulins. They are formed due to meltwater on top of the glacier and are often much deeper, and go all the way down to the bottom of the glacier. 

Given that glaciers are a heavy mass of ice, they move due to their weight. Most glaciers move slowly, but some can move as much as 160 feet a day. These fast-moving glaciers are known as galloping glaciers. 

When the glacier meets the coast, it is known as a tidewater glacier. Due to constant interaction with water, the edges of the giant ice glacier break into the water, and this process is known as calving. The large chunks of ice that break as a result of calving are known as icebergs. 

Zone of Accumulation 

The area in which glacial ice forms is known as the zone of accumulation. In this region, more snow accumulates every winter compared to the snow that melts away during summer. The snow that is buried inside turns into firn and eventually crystallizes into glacial ice. Once glacial ice is formed, it flows away from the zone of accumulation under its weight. In the case of alpine glaciers, the glacial ice flows downwards, but in the case of ice sheets, there is a lateral flow of accumulated ice. 

On the other hand, there is a zone of wastage. It is the glacier area that experiences more glacial ice melting than the formation of new ice. 

The line that separates the zone of an accumulation from the zone of separation is the snow line, which may be visible at the end of the summer season. 

The Impact of Climate Change on Glaciers

The formation of glaciers is a long process. It takes more than a hundred years to accumulate enough snow that it converts into glacial ice. However, uncontrolled human activities, including greenhouse gas production, contribute to an overall increase in the global temperature. And, of course, it will eventually have an impact on glacial ice. 

According to scientists, glacial ice is melting at a much higher rate than ever before. And studies claim the change will be much more drastic in the next thirty years. Alpine glaciers are under the most threat to global climate change. In addition, the ice sheets are also melting, contributing to an overall increase in global sea levels. 

One of the key concerns associated with the melting of glacial ice is that glaciers are a source of fresh water. But once it melts and becomes part of the ocean, it no longer remains as a water source. Hence, with melting glaciers, the concern is not just about the rising sea levels, but there can be other consequences as well as in the future.

Geology, Minerals

The Hardest Gemstones You Will Ever Find

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Sparkling Diamond
Diamond gem with reflection on blue background. Bigstock

You might think that the gemstone in the middle of your ring, earrings, or even your necklace is extremely hard and sturdy. However, some gemstones are harder than others. The chances are that you will find harder stones than the ones on your jewelry items. It is no wonder that over time, your jewelry starts to fade, look rotten, or the color starts to become unappealing.

The diamond is known to be the hardest gemstone, while talc is a soft mineral. The Mohs Hardness Scale is used to determine the hardness of gemstones. What this scale does is that it compares how resistant a mineral is by scratching it with ten different reference minerals of different levels of hardness. 

For instance, if Mineral B has successfully scratched Mineral A, it goes to show that Mineral A is not as strong and hard as Mineral B. A stone is put on the Mohs Hardness Scale as it finds its way up by being compared to the reference minerals. 

The Mohs Hardness Scale – What is it?

Gypse Arignac Mineral
Gypsum Arignac, France. Wikimedia CC

The Mohs Hardness Scale came into existence in 1812 and was made by Friedrich Mohs, a German mineralogist. The bigger mineralogy community started to use the scale by 1820. There were ten different minerals of different levels of hardness on the Mohs scale. 

 

  1. Talc
  2. Gypsum
  3. Calcite
  4. Fluorite
  5. Apatite
  6. Feldspar
  7. Quartz
  8. Topaz
  9. Corundum
  10. Diamond

These minerals were used as reference stones against which the hardness of other stones could be calculated.

Knowing How Hard a Gemstone is – Why is it Important? 

It is important to understand where your gemstone lies on the Mohs Hardness Scale, and this helps jewelers understand the kind of stone that will complement a certain jewelry piece best. For instance, even today, engagement rings are extremely popular. They are usually worn every single day, which means that they go through some rough conditions. 

If the stone in these engagement rings was not hard, it would rot or break over time. If a gemstone falls below seven on the Mohs Hardness Scale, it is considered to be unworthy of being used for an engagement ring.

Moreover, knowing how hard a gemstone is helps you understand how to care for the piece of jewelry and what to keep it away from. For example, a topaz is weaker than a diamond. This means that both of them should not be kept together; otherwise, the diamond may damage the topaz.

Alternative Measures of Hardness

There is another method of measuring gemstone hardness other than the Mohs Scale. This is known as the Vickers Hardness Scale which is used to measure the kind of indent made in a stone by a special diamond. The Vickers Scale can portray a clearer difference in hardness between two gems, while the Mohs Scale is not as linear. 

For instance, according to the Vickers Scale, diamonds are 300 percent harder than corundum. This falls from 9 to 10 on the Mohs Scale. Moreover, it shows that calcite is 25 percent harder than fluorite, falling from 3 to 4 on the Mohs Scale. This goes to show that the Vickers Scale is a lot more accurate, and provides detailed, reliable information.

Is Gemstone Toughness the Same Thing as Gemstone Hardness?

A 2 carat diamond being held up by tweezers
SMS©

The hardness of a gemstone is determined by how well it can withstand being scratched. On the other hand, the toughness of a gemstone depends on whether it can resist fracture if force and pressure are applied and how well it can resist that fracture. Stones of the same family may have varying levels of toughness based on the inclusions and residual stresses that show up because of heating and cutting processes.

Gemstone durability, also known as wearability, is important to understand. For example, an opal that has a hardness of 6 will be more vulnerable to fine scratches and loss of polish if it is worn as regularly as a ringstone. Quartz has a hardness of six and is known to be one of the most common minerals available on the planet. Since it is a component of dust, even if you wipe the dust off it with a soft material, it is likely to get scratched. Even though initially, the scratches will be minuscule and may only be seen under a microscope, over time, they will build up and become more visible. In contrast, a ruby that has a hardness of nine will continue to be bright for decades since it is a hard gemstone.

To learn more about how durable a gemstone is, it is essential to pay attention to its hardness and toughness. However, you should also focus on its stability. A gemstone’s stability depends on how well it can resist the loss of color over time that is caused by chemicals and how well it can withstand deterioration. 

For instance, weak acids can easily damage pearls, while skin oils and acids can cause turquoise to lose its color and fade into dirty green tones. Similarly, several other gems are vulnerable to environmental factors, making them likely to fade over a short period. That being said, most of the big gems that you have heard about are considered stable as they do not get destroyed by concentrated acids, nor do they lose their shape or color.

Geology

Best Blue Gemstones Used in Jewelry

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Blue Gemstones in a necklass
Image by starbright from Pixabay

Blue, the color of calmness and serenity, is one of the most popular gemstone color choices. Blue-colored gemstones are shiny and classy. This stunning color is said to be associated with stability, knowledge, depth, and power. Blue gemstones, in all their textures, shades, and vividness, can add sophistication to any jewelry piece, including earrings, rings, bracelets, necklaces, and pendants. 

Blue-colored gems are also becoming a popular gem color choice for wedding rings. For instance, the world’s most iconic engagement ring that belonged to Princess Diana entails a large blue sapphire. 

That being said, let’s explore some of the best blue gemstones that are popularly used in jewelry. 

Blue Sapphire

Sapphires are the most popular gem in the realm of blue gemstones. Even though sapphires are available in various colors, blue sapphire is the most preferred and well-known version. As part of the corundum family, the blue shade of a sapphire occurs as a result of the presence of titanium and iron. 

With a rating of 9 on the Mohs scale, sapphires are the second-hardest gemstone, making them highly resistant to scratches and breaking. Moreover, after diamonds, sapphire is probably the second-most sought-after colored gem for wedding rings. Since sapphire is the birthstone for September, sapphire-studded jewelry is a great choice for those born in the month. Additionally, although all sapphires are precious, the blue sapphire with a purplish tone is much pricier and desirable than the one with greenish hues. 

Aquamarine

Belonging to the beryl family, the aquamarine stone is a part of the same family as emeralds and morganite. With its name itself talking about the sea-blue color, aquamarine is one of the most stunning blue stones you can find. Besides diamonds and sapphires, aquamarines are popularly used in engagement rings, among other jewelry styles. Recognized for its distinctive pastel blue color, this beautiful gem evokes calmness. 

Aquamarines occur as big crystals and sparkle quite bright and beautiful when exposed to light. This stone has a vitreous to resinous luster. Also, aquamarines with intense deep blue hues are considered the most prized and expensive variety. 

With a rating of 7.5 – 8 on the Mohs scale, aquamarine is a pretty hard, sturdy, and durable stone that offers excellent clarity and doesn’t break easily, making it one of the best blue gemstone options for jewelry. 

Blue Diamond

Diamonds are found in a variety of colors. While the colorless variety of diamonds is the most popular type, blue diamonds are amongst one of the rarest and most expensive types of diamonds. Blue diamonds have identical properties to colorless diamonds, with exceptional brilliance and perfect hardness. Even though diamonds are sturdy and scratch-resistant, blue diamonds aren’t the toughest gemstone. You will have to use them with reasonable care to increase their longevity. 

Blue diamonds receive their color from the traces of boron present during the formation of the gemstone. Even though blue diamonds come in a range of shades, the fancy intense blue hue is usually a top choice. Pure blue-colored diamonds are typically considered to be the most beautiful and valuable gems, but blue diamonds with greenish tints are also quite popular. With the highest refractive index in the world, this stunning gem is a brilliant choice for almost any type of jewelry.

Blue Topaz

Blue topaz is another extremely rare blue gemstone. One of the most interesting facts about a topaz gem is that it is typically found in a colorless state. This gem is then put under intense heat treatments to create striking shades of blue. Naturally-occurring blue topaz gems are extremely rare and often occur as large crystals. These stones also show different colors when seen from different angles. 

Blue topaz is budget-friendly, but there are some expensive varieties of the stone as well. The most valuable and exclusive varieties of blue topaz include Swiss Blue, London Blue, and Sierra Blue, all of which are darker variations of the gemstone. Blue topaz is the right choice for various types of jewelry because of its toughness and durability. This gemstone is also a December birthstone.

Turquoise

Turquoise is another unique semi-precious gemstone that is the only gem with a color named after it. This gem usually forms when water seeps through mineral rocks, setting off a chemical reaction. Over a period of time, this reaction builds up and forms a beautiful, unique-looking gemstone. 

The turquoise gemstone is quite popular due to its vivid sky blue and green shades. Generally, opaque in nature, this stone typically includes dark web-like inclusions. However, inclusion-free, pure blue turquoise stones are considered to be the most valuable and desired ones. 

This ancient semiprecious gemstone is significantly soft, which is why it is often cut into cabochons and beads when used to make jewelry. This stone isn’t considered as durable as many other gemstone options, which is why it is mostly preferred in less delicate jewelry pieces. Also, when it comes to turquoise jewelry, you need to ensure that it receives extra care to maintain its luster.

Blue Tourmaline

Blue tourmaline is typically found in two assortments: Indicolite tourmaline and Paraiba tourmaline. While the Pairaba tourmaline gem displays a vivid and radiant blue color, the indicolite gem typically is found in light to dark shades of blue. Generally, blue tourmalines are tremendously rare and are also found in very small sizes, usually under a carat. 

While most blue tourmalines have greenish tones, the pure blue ones are considered more popular and prized. Blue tourmaline has a great hardness rating on the Mohs scale, making it one of the toughest and most durable gemstones. Tourmaline is also the birthstone for October, making tourmaline-studded jewelry a great gift option for those born this month. 

The Bottom Line

A few factors, including color, price, and hardness must be considered in order to determine the best blue gemstones to include in your jewelry piece. With so many unique characteristics, you can easily choose a beautiful gemstone for your jewelry. 

Geology

Best Yellow Gemstones for Wedding and Engagement Rings

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Yellow gemstone
Image by sara graves from Pixabay

Yellow gems are often an indicator of warmth, openness, and optimism. If you’re looking to try something other than colorless diamonds for your engagement or wedding ring, a yellow gemstone can be a great way to showcase your sunny disposition on your finger. 

Since wedding and engagement rings are everyday jewelry, we have put together a list of the best yellow gemstones that are unique and durable. 

When searching for a gemstone, you need to consider two main factors: 

    • Toughness – Measured by the Mohs hardness scale
    • Clarity – The transparency and inclusions or blemishes of a stone

Now that you know how to evaluate a gemstone, let’s jump in and have a look at the best yellow gemstones for engagement and wedding rings. 

Citrine

Stemming from the French word “citron” which means “lemon,” citrine is a type of quartz stone found in multiple shades, ranging from brownish-yellow to yellow-orange to lemon yellow. Although little odd, reddish-orange citrines are often considered more valuable than bright yellow citrines. 

This gemstone is pretty transparent and is often faceted even more to make it appear more lustrous. With a hardness of 7 on the Mohs scale, the durability of the stone resists scratching. Also, since quartz is found abundantly, it is easy to find citrines at budget-friendly prices. 

Citrines look amazing in white gold or rose gold settings. 

Yellow Diamonds

Diamonds are surely forever. With a hardness of 10 on the Mohs scale, colored or not, diamonds are the most durable and scratch-proof stones to exist. Although colorless diamonds are the most popular choice for engagement and wedding rings, if it does not truly capture your personality, a yellow diamond will save the day! 

With traces of nitrogen present during the formation of diamonds that gives them their yellow color, yellow diamonds are very commonly available. Canary yellow is the purest and most intense shade of yellow. However, a majority of yellow diamonds feature hints of other colors. Yellow diamonds with green tints are more popular and expensive, and yellow diamonds with brown tints are less-favored and less pricey. 

Just like colorless diamonds, yellow diamonds look great in every setting. 

Yellow Topaz

Signifying happiness and prosperity, yellow topaz is the birthstone for the month of November. Topaz receives its name from the Sanskrit word tapas, which means “fire.” This stone gets its name due to its fiery appearance. 

Topaz is available in an extensive range of bright and warm colors ranging from orange to dark yellow to a vibrant yellow. The darker variety of topaz is known as the Imperial Topaz. Although this variety is quite rare, which is why it’s valuable, its merry yellow shades are commonly available and are typically inexpensive. 

Topaz gems generally have a high clarity with minimal, almost non-visible inclusions. The brilliance of this stone is enhanced even more when it is faceted. With a hardness ranking of 8 on the Mohs scale, Topaz is a durable and scratch-resistant stone, making it suitable for everyday wear. 

Yellow Tourmaline

Tourmalines are often nicknamed the ‘rainbow gemstone’ since they can be found in almost every color. However, it can be quite challenging to find yellow tourmalines since they are quite rare. Vibrant yellow tourmalines get their color from iron and manganese during their formation. Pure and natural yellow tourmalines are difficult to find, so you can expect many inclusions. However, faceting helps enhance the brilliance of these gems. 

With a ranking of 7 to 7.5 on the Mohs hardness scale, this gemstone has considerably good durability only through proper maintenance. Tourmaline is seen as a symbol of strength and healing in many cultures. Yellow tourmalines are specifically believed to heal one’s ego and self-esteem. 

Yellow Sapphire

You probably imagine a big blue stone when you think of sapphires. Sorry to break it to you but not all sapphires are blue! Well, the truth is that sapphires are found in every color except for red. Made of corundum, sapphires turn yellow due to iron impurities during crystal formation. 

Yellow sapphires occur in many shades ranging from pale to vivid. The higher the iron content, the brighter the stone, and the more expensive it will be. Nevertheless, yellow sapphires are generally much less expensive than blue sapphires. Many sellers use heat treatment to improve the yellow coloring of sapphires. 

With a ranking of 9 on the Mohs hardness scale, sapphires are almost as hard as diamonds. They are resilient gems and can withstand breakage and scratches. However, it will require some maintenance to prevent clouding. 

Yellow Zircon

Zircon stems from the Persian word “zargun” that means  “gold-colored”. Zircons are available in various shades ranging from gold brown to vivid yellow. The bright yellow hues of this stone can be produced through heat treatment. When properly faceted, this beautiful stone produces a stunning brilliance that can even give competition to a diamond. 

Although zircons appear very similar to diamonds, the biggest drawback of this stone is that it is soft and brittle. With a hardness of 6 to 7.5 on the Mohs scale, zircons need to be used very carefully to prevent chipping or scratching. 

Yellow gems traditionally symbolize optimism, luck, self-esteem, and other positive energies and behaviors. Although yellow gems are an unconventional choice for engagement and wedding rings, they can be a great way to showcase the confidence and warmth in you. We hope this information on yellow gemstones will help you get started on your search for the perfect wedding or engagement ring!

 

Geology

Novarupta – The Most Potent Eruption of the 20th Century

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Image by Kanenori from Pixabay

It happened on June 6th, 1912!

The Novarupta-Katmai volcanic eruption in Alaska in 1912 became one of the most powerful eruptions of the 20th century. Even 109 years later, its status as one of the largest volcanic eruptions still remains.

In this post, we look at how it happened and the possibility that history might repeat itself again. 

The Eruption

On the morning of June 6th, 1912, Alaska residents were getting ready to start their upcoming fishing season. Back then, the population in the Alaska Peninsula was much lower than it is today. However, a few things never change, and earthquakes in the region are one of them. Even at that time, earthquakes were common in Alaska because of the region’s geological instability. 

As people were used to living in the region, over time, they realized that the earthquakes were not only getting more frequent but also stronger. Because of the frequency and intensity of these quakes, the two remaining families in the village left their homes for a safer place. 

And that’s when it happened. Around midday on June 6th, the skies over Katmai darkened and what happened next continued for the next 60 hours. The area didn’t see the sun during all these hours of a continuous volcanic eruption. 

Throughout the 60 hours of the constant eruption, the volcano spewed out around 6.7m3 of ash particles around 20 miles into the stratosphere (which extends around 30 miles above the earth’s surface). The ash-covered an area of around 3000 sq. miles, and the ash fell in amounts up to a foot that changed a nearby vast green valley into a wilderness known as the Valley of Ten Thousand Smokes. 

Impact of the Eruption

The region’s inhabitants were among the first people to experience the direct impact of the eruption. It was so loud that the blast was heard around 750 miles away. Moreover, the impact was not limited to sound. It had a major visual impact as residents witnessed a thick cloud of ashes that quickly rose towards the sky. 

Within the first few hours, this thick layer of ash began falling from the sky onto the nearby town of Kodiak. As the eruption continued for the next three days, the ashes covered the town up to one foot deep. As a result, the region’s inhabitants were forced to take shelter indoors as the outdoor environment was suffocating, making it difficult to breathe. The damage further continued as some of the buildings collapsed due to the heavyweight of the volcanic dust.

The impact was not limited to that region either. Within the next few days, the ash cloud traveled over western Canada and to several western U.S. states. By June 17th, the cloud was found in Algeria and then continued to spread to other regions, including China and India. While there were no deaths reported from the eruption, there was a lot of indirect impact in terms of loss to plants, animals, marine life, and agriculture, which continued for several years. 

The Formation of Valley of Ten Thousand Smokes

Novarupta Volacano
Valley of Knife Creek. Erin McKittrick, Ground Truth Trekking

Following the eruption, the National Geographic Society started sending expeditions to Alaska to investigate the damage.

During one such expedition in 1916, a few researchers traveled inland to the eruption area and found out that the valley of Knife Creek was completely barren.

Moreover, the ash was still hot, and thousands of jets of steam could be seen from the ground. Inspired by this observation, the valley was known as the “Valley of 10,000 Smokes”.

The Resulting Katmai Caldera and Novarupta Dome

During the initial observations, the Katmai Caldera volcano was originally thought to be a source of the eruption. However, it was a long time after the incident that researchers identified the original source as the Novarupta volcano. 

Can History Repeat Itself?

Novarupta is now silent and has been for quite some time. The last eruption reported from this volcano was the one in 1912 however, if you look at the history of Novarupta, it has erupted at least seven times in the last 4,000 years. Moreover, since the Alaska Peninsula is located on an active convergent boundary, we can expect future volcanic eruptions. Furthermore, given the location of Novarupta, it is likely that future volcanic eruptions will have a severe local and global impact, similar to what happened to Pompeii in 79 AD from the Mount Vesuvius volcano.

The local impact of potential volcanic activity anywhere can lead to a significant loss of life. Due to the potential impact of volcanic activity in this area of Alaska, the United States Geological Survey and others are closely monitoring these volcanoes. 

Furthermore, the impact of any future eruptions can have a devastating effect on the global climate. Studies indicate that a volcanic blast of this magnitude can modify the global surface temperature patterns and rainfall levels in several parts of the world.

Another possible reason to monitor these volcanoes is the danger of any future eruption on commercial air traffic. Jet engines experience enormous air pressure, and flying through the air containing fine ash particles can have a similar effect as sandblasting, which can cause extensive damage to the aircraft. Therefore, it is estimated that any future eruptions from Novarupta halt commercial air traffic across North America.

What Can We Do About It?

Unfortunately, eruptions like Novarupta are one of the natural disasters that we cannot prevent. However, the most we can do to control the situation is to assess the potential impact and develop a plan of action to minimize losses. With a history to look back to, there is a lot that we can learn from the eruption of 1912 and improve our chances of minimizing damage, injury, and death.

Geology

6 Longest Non-Polar Glaciers Around the World

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Glaciers, large masses of dense ice, are formed in high-altitude regions where the accumulation of snow is far greater and faster than the melting process. Over time, the layers of snow crystallize and form ice. The process of formation of glaciers takes centuries and even millennia. Surprisingly, glaciers are not just a unique feature of the polar caps but they are also found in many non-polar regions of the world. High mountain ranges in the former USSR, Pakistan, and the Americas are also home to some of the world’s largest non-polar glaciers. Below is a list of the seven longest non-polar glaciers in the world.   

Fedchenko Glacier, Tajikistan 

The world’s longest glacier outside the polar world is the Fedchenko glacier situated in the Central Asian country of Tajikistan. The glacier is around 45 miles long and covers an area of 350 square miles. The Fedchenko Glacier flows north from the ice field of Revolution Peak and receives ice from dozens of other smaller glaciers. The thickness of ice in the middle of the Fedchenko glacier is approximately 3,280 feet. The giant mass of ice can cover a distance of up 26 inches every day and forms the headstream of River Surkhab and the Amu Darya. 

It was discovered in 1871 by a Russian expedition and is named after the Russian explorer A.P. Fedchenko. Parts of this iceberg were explored later in 1928. Over time, the glacier has experienced a significant loss of ice. Climate change and global warming have dramatically reduced their size since the second half of the last century. 

Siachen Glacier, Indo-Pak Border 

The Siachen is the second-longest non-polar glacier in the world lying in the Karakoram Range near the border of India and Pakistan. It is 47 miles long and covers an area of 270 square miles. The region is home to many smaller glaciers and a number of fast-flowing surface streams.  

Climate change has significantly affected almost every part of the world and the Siachen glacier is no exception. Between the years 1989 and 2009, this area of ice was reduced by 2.2 square miles. Human presence in the region has further accelerated the melting, as this mountain of ice has been a source of conflict between military conflict for decades. The highest battlefield on Earth provides freshwater which enters the River Indus of Pakistan and the Ganges in India.

Biafo Glacier, Pakistan 

The Biafo Glacier is another long non-polar glacier located in the Karakoram range in Pakistan. The 40-mile-long mountain in Gilgit-Baltistan meets Hispar Glacier, another 30-mile-long glacier, and forms the largest glacial system outside the polar region. This ice formation acts as a bridge between the two ancient kingdoms of the mountains; The Nagar and Baltistan. The Biafo glacier provides a trek with spectacular sights and traces of wildlife all along.  

The glacial system is largely affected by the changing global climate. The rising temperature has destabilized the movement of these ice formations and has altered the level of rain and snowfall in the region; consequently, these changes have resulted in flooding and intense heat waves not only in Pakistan but in other neighboring countries as well. 

Bruggen Glacier, Chile 

The Bruggen Glacier, also known as the Pio XI Glacier, is located in southern Chile. With a length of 40 miles, it is the fourth-largest glacier in the non-polar region and the longest glacier in the Southern hemisphere.  The glacier continued to advance towards the sea and covered a distance of more than three miles between 1945 and 1976. 

Despite being one of the largest glaciers in the nonpolar region of the world, the Bruggen glacier is one of the least studied glacial areas in the world. However, considering its pattern of movement, it can be concluded that the glacier experienced periods of enhanced movement followed by retreat periods. This effect is in addition to climate change which is negatively affecting the glaciers around the world. 

Baltoro Glacier, Pakistan 

The Baltoro glacier is located in the mountain range of the Karakoram in the Baltistan region of northern Pakistan. It covers an area of 23 square miles and the length of the centerline is more than 35 miles. The second highest mountain in the world, K2 is located around 7 miles north of the tongue of the main glacier. 

Despite its location in a remote and politically unstable region of Pakistan, this glacier is extensively studied by geologists. This glacier is of unique importance to geologists because of its extensive debris cover. 38% of the area of the glacier is covered with debris. When it comes to these types of ice formations, debris accumulation follows a certain pattern of increasing thickness. Ongoing land sliding and mudflow have led to an increase in the thickness of debris in the Baltoro glacier. As of now, the debris thickness in Baltoro glaciers has reached almost 10 feet, which is a major concern for geologists. 

South Inylchek Glacier, Kyrgyzstan, and China 

Another tourist-friendly destination, the South Inylchek Glacier is located on the borders of Kyrgyzstan and China. With a length of over 60 miles and more than 300 square miles, the Inyichek glacier is the sixth-longest nonpolar glacier. It is divided into two sections and covers more than 100 peaks of varying heights with snow and ice. 

It is a place of incredible natural beauty where climbers around the world can enjoy the trek along with breathtaking aerial views.