Color
: Colorless, yellow, brown, sometimes green, blue, reddish,
black
Mohs’
hardness : 10
Specific gravity : 3.47-3.55
Cleavage : Perfect
Crystal system : cubic
Chemical composition : carbon
Refractive index : 2.417-2.419
Double refraction : none
Flourescence : Variable ; colorless and yellow : mostly
blue ; brown and green : mostly green
The name diamond refers to its hardness
(Greek – Adamas, unconquerable). There is nothing comparable to it in hardness;
it is therefore nearly imperishable. Its cutting resistance is 140 times greater
than that of corundum. However the hardness of a diamond is different in the
individual crystal faces. This allows one to cut diamond with a diamond (or
diamond powder, in which according to statistical probability – various diamond
hardnesses occur). Care has to be taken during mounting because of perfect cleavage.
Its very strong luster enables the experienced eye to differentiate between
a diamond and its imitations.