Biotite Mica
K(Mg,Fe)3AlSi3O10(OH)2
Category
Browse igneous specimens identified by the Rock Identifier community.
Biotite Mica
K(Mg,Fe)3AlSi3O10(OH)2
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
Milky Quartz Pebbles
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Garnet (almandine or pyrope variety)
Silicate mineral Group: (Fe, Mg, Mn, Ca)3(Al, Fe, Cr)2(SiO4)3
Milky Quartz
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Rough Green Sapphire (Corundum)
Corundum (Al2O3 - Aluminum Oxide with trace elements)
Citrine Quartz
Silicon Dioxide (SiO2)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Labradorite (Carved)
(Ca, Na)(Al, Si)4O8
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Amethyst
Amethyst (variety of Quartz, SiO2)
Fluorite (Rainbow, Purple-Blue Tumbled)
Calcium Fluoride (CaF2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Pyrite (Fools Gold)
Iron Sulfide (FeS2)
Citrine
Silicon Dioxide (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Fluorite
Calcium fluoride (CaF2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Peacock Ore (Bornite or Chalcopyrite treated with acid)
Bornite (Cu5FeS4) or Acid-washed Chalcopyrite (CuFeS2)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Milky Quartz
Quartz / Silicon Dioxide (SiO2)
Smoky Quartz (Rough Specimen)
Silicon Dioxide (SiO2)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Pyrite
Iron Disulfide (FeS2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Agate (specifically a small Chalcedony nodule)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Gneiss (specifically a water-worn pebble)
Gneiss
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Yellow Calcite
Calcium Carbonate (CaCO3)
Chalcopyrite
Chalcopyrite (CuFeS2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Blue Sapphire
Corundum (Al2O3) with iron and titanium impurities
Milky Quartz
Quartz (Silicon Dioxide, SiO2)