the characteristic

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.
Crystal habit Octahedral
Crystal system Isometric-Hexoctahedral (Cubic)
Cleavage 111 (perfect in four directions)
Fracture Conchoidal - step like
Mohs Scale hardness 10
Luster Adamantine
Polish luster Adamantine
Refractive index 2.4175–2.4178
Optical Properties Singly Refractive
Birefringence none
Dispersion .044
Pleochroism none
Ultraviolet fluorescence colorless to yellowish stones - inert to strong in long wave, and typically blue. Weaker in short wave.
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.
Streak White
Specific gravity 3.52 (+/- .01)
Density 3.5-3.53 g/cm³
Diaphaneity Transparent to subtransparent to transluce