History of Diamond

	Revision 23 . . (edit) December 19, 2001 11:05 pm by (logged).200.130.xxx [links, factual corrections, and spelling]
	Revision 22 . . December 3, 2001 7:05 am by Vicki Rosenzweig [clarified "air pressure" and instability]
	Revision 21 . . December 3, 2001 7:04 am by Vicki Rosenzweig [copyedit, mostly to remove Excessive Capital Letters]
	Revision 20 . . November 13, 2001 12:25 am by Dmerrill [deleting folklore section as I promised almost a week ago, since no context or references have been provided. I'd love to see something like it be put back, but references and context are not optional]

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Difference (from prior major revision) (minor diff, author diff)

Changed: 1c1

Diamond is one of the natural allotropes of carbon (the main one being graphite). Sometimes known as adamant, it is the hardest known naturally occuring material, scoring 10 on the old Mohs hardness scale. The only other material which is as hard is boron nitride in a form structurally identical to diamond; a currently hypothetical material, [beta carbon nitride]?, may also be as hard or harder in one form.

Diamond is one of the natural allotropes of carbon (the main one being graphite). Sometimes known as adamant, it is the hardest known naturally occurring material, scoring 10 on the old Mohs hardness scale. The only other material which is as hard is boron nitride in a form structurally identical to diamond; a currently hypothetical material, [beta carbon nitride]?, may also be as hard or harder in one form.

Changed: 6c6

The diamond derives its name from the Greek Adamas, "uncorrupted." Diamonds occur in a variety of colours - steel, white, blue, yellow, orange, red, green, pink and black.

The diamond derives its name from the Greek Adamas, "uncorrupted." Diamonds occur in a variety of colours - steel, white, blue, yellow, orange, red, green, pink and black. Coloured diamonds contain impurities that cause the coloration, pure diamonds are always translucent and colourless.

Changed: 8c8

In the late 18th century, diamonds were demonstrated to be made of carbon by the rather expensive experiment of igniting a diamond (by means of a burning-glass) in an oxygen atmosphere and showing that [carbonic acid]? gas (carbon dioxide) was the product of the combustion. The fact that diamonds are combustible bears further examination because it is related to an interesting fact about diamonds. Diamonds are carbon Crystals that form deep within the Earth under high temperatures and extreme pressures. At air pressure diamonds are not stable and slowly decay into graphite. So, despite [De Beers]?' ad campaign, diamonds are definitely not forever.

In the late 18th century, diamonds were demonstrated to be made of carbon by the rather expensive experiment of igniting a diamond (by means of a burning-glass) in an oxygen atmosphere and showing that [carbonic acid]? gas (carbon dioxide) was the product of the combustion. The fact that diamonds are combustible bears further examination because it is related to an interesting fact about diamonds. Diamonds are carbon Crystals that form deep within the Earth under high temperatures and extreme pressures. At surface air pressure (one atmosphere), diamonds are not as stable as graphite, and so the decay of diamond is thermodynamically favourable (ΔH = -2KJmol-1). So, despite [De Beers]?' ad campaign, diamonds are definitely not forever. However, owing to a very large kinetic energy barrier, diamonds will not decay into graphite under normal conditions.

Changed: 18c18,19

Koh-i-noor

*Koh-i-noor *[Millenium star]?