Geology Home Page physical geology historical geology planetary gems
Roger Weller, geology instructor
by Katlyn Vass
Diamonds are the hardest rocks known to man. Diamond means unbreakable or others like to say invincible. The unique qualities a diamond has makes it one of the most valued substances on Earth. Diamonds have a unique, three-dimensional molecular structure that makes it much less brittle than other rocks. Diamonds rank number one on Moh’s hardness scale. Diamonds are usually not colored. However some diamonds have been found to be colored. Diamonds are made in the Earth’s mantle. They are made up of carbon. However, they are put under high pressure and high heat. The process takes about 1-3 billion years to form naturally. Some small diamonds form in meteors. Diamonds can also be formed synthetically. Only 20% of diamonds are used for jewelry and 80% is used for industrial purposes.
Where are diamonds found?
Most natural diamonds are found in kimberlites or lamproites. These are structures of rocks that are formed through volcanic activity. Diamonds can also be found where no volcanic activity has occur due to the fact that water and erosion might have taken them somewhere else. This is what is called a placer deposits. Diamonds are found in over 35 countries today.
When were diamonds first discovered?
Diamonds are a modern day commodity. In the fourth century, India was the only source fro diamonds. By 1725, Brazil had also discovered diamonds. Then, in the 1870’s, they were finally discovered in South Africa. This is what eventually led to the dramatic increase in the diamond supply. Today’s diamonds are often thought to only come from South Africa. However, this is completely not true. Diamonds today are a complete worldwide resource.
WHAT WERE THE INITIAL USES OF DIAMONDS?
Diamonds were originally used to polish axes. Not the axe that cuts down a tree, but an axe that was used to polish ceremonial burial axes. The Chinese would polish the axes as a sign of respect for whoever was being laid to rest. The axe itself was made of corundum. Corundum is the second hardest naturally occurring substance on Earth. Diamonds are also not the hardest substance on Earth.
HOW ARE DIAMONDS FORMED?
Diamonds are formed almost 100 miles below Earth’s surface. They are formed in
the upper mantle. The mantle is very hot and contains a lot of pressure. The
weight of the overlying rock and that combination are what is necessary to grow
diamond crystals. However there is no way for humans to reach the upper mantle.
The diamonds that are at the surface of the Earth are the one’s brought by
How many diamonds are in the world today?
When diamonds were first discovered, they were thought to be a
rare commodity. When India first discovered diamonds, their maximum production
annually was 50,000 to 100,000 carats. In today’s century, the production
annually is 100 million carats. The same goes for other nations too. There is
also major production sources in Australia, Botswana, Russia, and Congo
Republic. However, India, Brazil, and South Africa are still major produces in
value and volume.
What are the uses for diamonds today?
When people are asked “What is a diamond used for?” They would
probably say jewelry. This is true. However, diamonds are mostly used in the
industrial field. Diamonds are known for their hardness and therefore are
helpful to grind down, cut, or even drill other materials. Many car companies
use drills that contain diamonds to cut the metals made for cars and other heavy
WHY ARE DIAMONDS SUCH A WANTED ITEM?
Diamonds are wanted for their luster and their longevity. They
can be easily given down as a family heirloom or a ring. They last forever and
do not lose their shape. They can be washed, worn, dropped, etc. You name it and
it can be done. They are looked at as signs of love. This is why diamonds are so
wanted. They are used to show love. They are everlasting.
Kohn, David. “Diamonds: A History”. CBSNews. May 8, 2002. www.cbsnews.com . 14 Nov. 2016.
Lineburry, Cate. “Diamonds Unearthed”. Smithsonian. Dec. 2006. www.smithsonianmag.org . 14 Nov. 16.
Hamilton, James. “What is a Diamond?” Science Views. 2008. www.scienceviews.com . 14 Nov. 2016