a crystalline rock that can be cut and polished for jewelry

a hydrated aluminium phosphate mineral (AlPO4·2H2O).

a chatoyant gemstone that is usually a metamorphic rock that is a golden to red-brown colour, with a silky luster.

a blue, green, or reddish-brown feldspar mineral of the plagioclase series: used as a decorative stone..

a reddish-brown to black mineral consisting of titanium oxide in orthorhombic crystalline form: occurs in silica veins.