All diamonds are erupted to the surface of the earth from deep within the mantle, where diamonds are formed. Diamonds are mined on every continent on earth except Europe and Antarctica.
All diamonds are formed from carbon.
Diamonds are formed in a crystalline structure from carbon. Not all crystals are formed from carbon; not all crystals are diamonds.
Not all diamonds come with certification of authenticity.
All diamonds are formed from carbon.
All diamonds are found in the earth.
You may be thinking of gem-quality and industrial diamonds. About 80% of all diamonds mined are industrial diamonds.
All diamonds are 'pure carbon diamonds', even the 80% of all diamonds mined that are not gem quality, and rated as industrial diamonds. This means that anyone selling a diamond is selling a 'pure carbon diamond'.
Industrial diamonds come from diamond mines, in fact about 75% of all diamonds mined are industrial diamonds.
About 80% of all diamonds mined are industrial diamonds, and these are the most commonly used diamonds everywhere. This use of diamonds is not measured in number of diamonds, but in tons.
There are numerous 'kinds' of diamonds -- too many to list. The number of diamonds cannot be determined, since not all diamonds have been mined to date.
These diamonds are industrial diamonds. About 80% of all diamonds mined are classified as industrial diamonds, leaving only about 20% to be graded as gemstones.
In their natural state, as they are mined from earth, all diamonds are 'unrefined'. Yes, diamonds are scarce.