Amethyst
Silicon Dioxide (SiO2) containing iron impurities
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) containing iron impurities
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Amethyst (Quartz)
Silicon Dioxide (SiO2)
Olivine
Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2)
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.
Pearl
Biogenic CaCO3 (Aragonite)
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite inclusions
Peridot
Olivine (Mg, Fe)2SiO4
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Pearl
Aragonite and Calcite (CaCO3) with Conchiolin
Quartz
Quartz (SiO2 - Silicon Dioxide)
Moonstone (specifically Cat's Eye or Gray Moonstone)
Orthoclase (Potassium Aluminum Silicate) with the formula (K,Na)AlSi3O8
Moonstone (Feldspar variety)
Orthoclase Feldspar (KAlSi3O8)
Silicon Carbide (Carborundum)
Silicon Carbide (SiC) / Moissanite (natural)
Turquoise
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
White Quartz
Quartz (SiO2)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Quartz (in a rock matrix)
Quartz (SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Citrine
Silicon Dioxide (SiO2) - Macrocrystalline Quartz variety
Moonstone (Orthoclase Feldspar)
(K,Na)AlSi3O8
Aquamarine
Beryl (Be3Al2Si6O18)
Sandstone (Quartz-rich)
Arenite (SiO2)
Calcite
Calcite (CaCO₃)
Amethyst (Rough Crystal)
Silicon Dioxide (SiO2 with ferric iron impurities)
Citrine
Quartz (SiO₂) variety
Fairburn Agate
Cryptocrystalline Quartz (SiO2)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate - (Mn,Fe,Mg,Ca)SiO3)
Amethyst
Silicon Dioxide with trace Iron (SiO2)
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Sunstone
Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)
Tourmaline (Multi-colored)
Complex Borosilicate (Na,Ca)(Li,Mg,Al,Fe)3Al6(BO3)3Si6O18(OH)4
Peridot in Basalt
Olivine ((Mg, Fe)2SiO4) in Basalt
Carnelian
Carnelian (Silica, SiO2)
Amazonite
K(AlSi3O8)
Limonite with Opal infusion
FeO(OH)·nH2O (Limonite) / SiO2·nH2O (Opal)