Travertine (Tufa)
Calcium Carbonate (CaCO3)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Chert (Grey-Green Var.)
Silicon Dioxide (SiO2)
Amethyst Geode
Silicon Dioxide (SiO2) - Amethyst variety of Quartz
Milky Quartz
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Obsidian and Phantom Quartz
Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)
Citrine
Crystalline Quartz (SiO2) with iron impurities
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Smoky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
Jasper
Silicon dioxide (SiO2) with iron inclusions
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Amethyst and Citrine (Ametrine Mix)
Silicon Dioxide (SiO2) with Fe3+ impurities
Blue Tiger's Eye
Crocidolite in Quartz (altered)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Amethyst
Silicon Dioxide (SiO2) containing iron impurities
Amethyst (Quartz)
Silicon Dioxide (SiO2)
Olivine
Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
Red Jasper
Jasper (Silicon Dioxide with Hematite inclusions), SiO2
Red Jasper
Jasper (Silicate mineral - SiO2)
Yellow Jasper
Jasper (SiO2) with iron hydroxide inclusions
Pearl
Biogenic CaCO3 (Aragonite)
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
Wood Beads (Palmwood/Ebony)
Various species for wood, but often refers to woods like Palmwood (e.g., Borassus flabellifer) or Ebony (Diospyros spp.) for their distinctive grain and hardness.
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite inclusions
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2)
Moonstone (specifically Cat's Eye or Gray Moonstone)
Orthoclase (Potassium Aluminum Silicate) with the formula (K,Na)AlSi3O8
Moonstone (Feldspar variety)
Orthoclase Feldspar (KAlSi3O8)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Turquoise
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Silicon Carbide (Carborundum)
Silicon Carbide (SiC) / Moissanite (natural)
Peridot
Olivine (Mg, Fe)2SiO4
Pearl
Aragonite and Calcite (CaCO3) with Conchiolin
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Citrine
Silicon Dioxide (SiO2) - Macrocrystalline Quartz variety