Obsidian
Volcanic glass (Mainly SiO2)
Category
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass (Mainly SiO2)
Chrysocolla and Azurite in Matrix
Hydrated copper phyllosilicate (Chrysocolla - Cu2H2Si2O5(OH)4) and Copper carbonate (Azurite - Cu3(CO3)2(OH)2)
Nuummite
Antophyllite-Gedrite (Orthorhombic amphibole)
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
Moonstone (Feldspar)
Orthoclase/Albite ((K,Na)AlSi3O8)
Pegmatite
Coarse-grained Igneous Rock (Granitic Pegmatite)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions
Citrine Quartz
Silicon Dioxide (SiO2)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Carnelian
Carnelian (a variety of Chalcedony) - SiO2
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Jade
Jadeite or Nephrite
Banded Agate (specifically Lake Superior Agate style)
Agate (Cryptocrystalline Quartz), SiO2
Blue Banded Agate (Dyed)
Silicon Dioxide (SiO2) - Chalcedony variety
Jasper
Silicon dioxide (SiO2)
Agate
Silicon Dioxide (SiO2)
Yellow Jasper (Iron-stained Quartz)
Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)
Black Opal
Hydrated Silica (SiO2·nH2O)
Jasper
Jasper (Silicon Dioxide, SiO2)
Dyed Pink Agate (Crackled)
Silicon Dioxide (SiO2) - Chalcedony variety
Moonstone
Orthoclase/Albite (KAlSi3O8 / NaAlSi3O8) with Adularescence
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Jasper
Jasper (Silicon Dioxide) - SiO2
Angelite
Anhydrite (Calcium Sulfate, CaSO4)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Olivine (Peridot in gem form)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Chrysoprase
Chrysoprase (a variety of Chalcedony, SiO₂)
Brown Jasper (Likely)
Jasper (Cryptocrystalline Silicon Dioxide - SiO2)
Turquoise
Hydrous phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Beryl (Emerald Variety)
Beryllium aluminum silicate (Be3Al2(SiO3)6) with chromium/vanadium traces
Moissanite
Silicon Carbide (SiC)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
Pearl (Biogenic)
Nacre / Calcium Carbonate (CaCO3)
Citrine
Silicon dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe) impurities
Honey Calcite Sphere
Calcium Carbonate (CaCO3)
Rhodonite in Matrix
Rhodonite (Manganese Silicate) - (Mn2+,Fe2+,Mg,Ca)SiO3