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GEMS
Lesson 4 - Page 1

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 HOPE DIAMOND

Diamonds are beautiful, dazzlingly bright gemstones that are composed of carbon. Diamond is the hardest known substance due to carbon atoms forming a tightly bound three dimensional structure. It is strange that a soft mineral, graphite is also made of carbon, but the atoms are far apart.

Diamonds form naturally within the Earth in a rare volcanic occurrence that brings magma from the upper mantle in a pipe. There are only a few places to find kimberlite pipes like India, Brazil, South Africa, and even in the state of Arkansas. Many times erosion will cause diamonds to settle in river beds, where they are mined as placer deposits. Diamonds can be artificially made, but usually do not have the clarity or brilliance of a natural diamond. The crystal shape of a diamond is octahedral. However, diamonds have many cleavage surface which allows them to be faceted. A diamond cutter is skilled in the cleavage planes, and can use diamond dust and oil to smooth the surface to create the splendor that diamonds produce.


Kimberlite pipe

Oppenhimer the largest Uncut diamond
(253.7 carats)
 

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