Diamond
A scattering of round-brilliant cut diamonds shows off the many reflecting facets.
General
Category	Native Minerals
Chemical formula	C
Identification
Molecular Weight	12.01 u
Color	Typically yellow, brown or gray to colorless. Less often in blue, green, black, translucent white, pink, violet, orange, purple and red.[1]
Crystal habit	Octahedral
Crystal system	Isometric-Hexoctahedral (Cubic)
Cleavage	111 (perfect in four directions)
Fracture	Conchoidal (shell-like)
Mohs Scale hardness	10[1]
Luster	Adamantine[1]
Polish luster	Adamantine[1]
Refractive index	2.4175–2.4178
Optical Properties	Singly Refractive[1]
Birefringence	None[1]
Dispersion	0.044[1]
Pleochroism	None[1]
Ultraviolet fluorescence	Colorless to yellowish stones; inert to strong in long wave, and typically blue. Weaker in short wave.[1]
Absorption spectra	In pale yellow stones a 415.5 nm line is typical. Irradiated and annealed diamonds often show a line around 594 nm when cooled to low temperatures.[1]
Streak	White
Specific gravity	3.52 (± 0.01)[1]
Density	3.5-3.53 g/cm³
Diaphaneity	Transparent to subtransparent to translucent