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“diamonds”
The ultimate gemstone, having few weaknesses and many strengths: It is well known that diamonds are the hardest substances found in nature, but few people realize that diamonds are four times harder than the next hardest natural mineral, corundum (sapphire and ruby).
Diamonds are usually utilized as gemstones and an abrasives, as well as in scientific uses.
This entry is located in the following unit:
Geology or Related Geological Terms +
(page 5)
diamonds, a diamond
These are the hardest and most lustrous gems because they retain their brilliance and polish for many generations.
They are a form of carbon that has been crystallized under great pressure and very high temperatures.
The two major sources for diamonds are South Africa and Australia.
"In 1695, two scientists obtained a diamond from a rich patron and heated it by using a lens to focus light on it. The diamond disappeared. Diamond is made of carbon, and it burns just as coal will when it is heated strongly enough."
This entry is located in the following unit:
Gemstones or Precious and Semi-Precious Stones +
(page 1)
(the four gemstones which are most valuable are diamonds, sapphires, rubies, and emeralds; and anyone would be impressed with a gift of a diamond, a sapphire, an emerald, or a ruby piece of jewelry)