Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Blue Sapphire (Ceylon)
Corundum (Al2O3) with traces of Iron and Titanium
Fluorite
Calcium Fluoride (CaF2)
Amazonite
Amazonite (KAlSi3O8)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Sodalite
Sodalite: Na8(Al6Si6O24)Cl2
Citrine Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Amazonite
Potassium Feldspar (Microcline) - K(AlSi3O8)
Amethyst
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide with Iron impurities), SiO2
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe) impurities
Quartzite
Quartzite (primarily SiO2)
Lazulite
Lazulite (MgAl2(PO4)2(OH)2)
Carnelian
Silicon dioxide (SiO2) with Iron Oxide impurities (Fe2O3)
Gold-Bearing Quartz
Silicon Dioxide with Native Gold (SiO2 + Au)
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Baltic Amber
Succinite (Polmerized conifer resin)
Serpentine Schist with Quartz Vein
Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).
Green Fluorite
Calcium Fluoride (CaF2)
Turquoise
Hydrous phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Carnelian Agate
Silicon Dioxide with Hematite impurities (SiO2 + Fe2O3)
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Amazonite
K(AlSi3O8) - Microcline variant
Banded Agate (specifically Carnelian Agate / Sardonyx)
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz (Milky or Rough Quartz)
Silicon Dioxide (SiO2)
Amazonite
Potassium Aluminum Silicate (KAlSi3O8)
Amethyst (Quartz variety)
Silicon Dioxide (SiO2) with iron impurities
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Amethyst (Druzy Cluster)
Silicon Dioxide (SiO2) with Fe3+ impurities
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
Amazonite
K(AlSi3O8), Microcline (potassium feldspar)
Pearl
Calcium carbonate (CaCO3) - Aragonite/Calcite variety
Amethyst
Silicon dioxide (SiO2) containing traces of iron and manganese
Jasper
Silicon dioxide (SiO2) with impurities
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium impurities)
Yellow Jasper
Silicon Dioxide with Iron inclusions (SiO2)
Granite
Granite (a felsic intrusive igneous rock)