Diamond Trivia

A diamond is the hardest natural substance on earth, but
if it is placed in an oven and the temperature is raised
to about 1405 degrees Fahrenheit, it will simply vanish,
without even ash remaining. Only a little carbon dioxide
will have been released.
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Diamonds are formed over a period of a billion or more
years deep within earth's crust - about 90 miles deep -
and is pushed to the surface by volcanoes. Most diamonds
are found in volcanic rock, called Kimberlite, or in the
sea after having been carried away by rivers when they
were pushed to the surface.
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A diamond is 58 times harder than the next hardest mineral
on earth, corundum, from which rubies and sapphires are
formed. It was only during the 15th century that it was
discovered that the only way to cut diamonds was with other
diamonds. Yet, diamonds are brittle. If you hit one hard
with a hammer, it will shatter.
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The world's largest diamond was the Cullinan, found in
South Africa in 1905. It weighed 3,106.75 carats uncut. It
was cut into the Great Star of Africa, weighing 530.2
carats, the Lesser Star of Africa, which weighs 317.40
carats, and 104 other diamonds of nearly flawless color
and clarity. They now form part of the British crown jewels.
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Not all diamonds are white. Impurities lend diamonds a
shade of blue, red, orange, yellow, green and even black.
A green diamond is the rarest. It is not the rarest
gemstone, however. That title goes to a pure red ruby.
Diamonds actually are found in fair abundance; thousands
are mined every year. 80% of them are not suitable for
jewelry - they are used in industry. Only diamonds of
higher clarity are sourced to the jewelry stores.
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A diamond carat differs from a gold carat. The gold carat
indicates purity - pure gold being 24 carats. One diamond
carat is 0.007055 oz. The word carat derives from the carob
bean. Gem dealers used to balance their scales with carob
beans because these beans all have same weight.