54 entries in total. Tap a term to open the illustrated definition.
A property of anisotropic gemstones in which an entering light ray s…
A property of cubic-system gemstones and amorphous materials in whic…
A number that describes how strongly a gemstone bends light entering…
The ratio of a gemstone's weight to the weight of an equal volume of…
Resistance to scratching, expressed on the 1-10 Mohs scale. Diamond …
A tendency to split along specific crystallographic planes. Stones w…
The ability of a gemstone to split white light into its spectral col…
The classification of crystals by the symmetry of their internal ato…
The property of anisotropic gemstones of showing different colours w…