Crystal system: cubic
Chemical Formula/composition: carbon (only gemstone that is composed of a single element)
Crystal habit: octahedra, cubes, tetrakishedrons, twinning possible
Hardness: 10 (hardest mineral)
Specific gravity: 3.514 - 3.518
Luster: adamantine to greasy
Toughness: good
Cleavage: perfect, octahedral
Optics: refractive index: 2.417 ND, Birefringence: none (isotropic), Dispersion: 0.044 (extremely high)
Color: colorless, pale yellow less commonly red, orange, yellow, pink, green, blue, brown, and black (carbonado)
Other: U.V. fluorescence commonly nonfluorescent, fluoresces blue, green, yellow or red
Varieties: gem quality, industrial quality (called bort or carbonado).
Localities: Southern Africa, Brazil, Canada, China, Russia, British Guiana, India, in the USA (Arizona, Nevada, and Montana, and most importantly Pike County, Arkansas), and space dust/meteroites
Common simulants CZ = cubic zirconia, GGG = gadolinium gallium garnet, SiC = Silicon Carbide aka Moissonite, Strontium titanate, YAG = yttrium aluminum garnet, other simulants include "paste", a type of high refractive index glass
Synthetics: Synthetic gem quality diamonds are now being marketed by several firms in the USA; other major sources include: Russia and De Beers

Detailed Subject descriptions

Diamond Mining

Diamond Cutting

Diamond Marketing

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