Minerals and Gemstones

Abalone-Biotite

Stone Formula Group Other Information
Abalone
Variable Organic colourless-shell material found in warm waters
Actinolite
Ca2(Mg,Fe)5 Si8O22(OH)2 Silicates green-variety of nephrite
Agate
SiO2 Silicates colour depends on impurities-form of chalcedony
Alabaster
Ca SO42H2O Sulphates usually white-variety of gypsum-forms by evaporation
Almandine
Fe3Al2(SiO4)3 Silicates red-a garnet
Amazonite
KAlSi3)8 Silicates green/turq-a feldspar
Amber
- Organic yellow/brown-fossil resin of coniferous trees
Amethyst
SiO2 with Fe Oxides violet-variety of quartz-colour due to presence of Fe oxide
Andradite
Ca3Fe2Si3O12 Silicates green/black-member of the garnet family
Angelite
Angelite CaSO4 Sulphates

aka anhydrate light blue-similar to gypsum

Annabergite
Annabergite Ni3(AsO4)2 8H2O Arsenates white/green-forms in nickel veins
Apatite
Ca5(PO4)3 (F,Cl,OH) Phosphates colourless (appears blue/green)-source of phosphorous
Apophyllite
Apophyllite

KCa4Si8O20 (FOH)8H2O

Silicates white/colourless-usually transparent
Aquamarine
Be3Al2Si6)18 Oxides blue variety of beryl
Aragonite
CaCO3 Carbonates colourless-similar to calcite-different crystal structures
Arkose
- Sedimentary a sandstone-(feldspar and quartz)-forms in bedding layers
Astrophyllite
Astrophyllite (K,Na)3 (Fe,Mn)7Ti2Si8 O24(O,OH)7 Silicates forms bladed crystals-bronze to golden yellow
Atacamite
Cu2Cl(OH)3 Halides green-an evaporite-source of copper
Augite
(Ca,Mg,Fe )2Si2O6 Silicates dark green/black-a pyroxene-formed beneath surface
Aventurine
SiO2 with inclusions Oxides brown/green-colour due to inclusions
Azurite

Cu3(CO3) 2(OH)2

Carbonates blue-source of copper-known as blue malachite
Baryte
BaSO4 Sulphates white-source of barium
Basalt
- Extru Igneous black/brown-formed from solidified lava
Beryl
Be3Al2Si6O18 Silicates colourless-source of beryllium
Biotite
K(Mg,Fe)3Al Si3O10(OH,F)2 Silicates black/brown-mica

Chemical Symbols