Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
Fossil bivalve shell
Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized
Amber (Copal)
Succiniferous Resin
Chalcedony
Cryptocrystalline Quartz (SiO2)
Amber
Succinite (formula varies, primarily C10H16O)
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Chert / Flint
Silicon Dioxide (SiO2)
Amber
Succinite (specifically for Baltic amber); Approximate formula: C10H16O
Petrified Wood
Silicified Wood (SiO2)
Lapis Lazuli (polished cabochon)
Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)
Obsidian
Volcanic Glass (Amorphous Silica)
Petrified Wood
Silicified wood (principally SiO2)
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)
Jasper
Jasper (Silicon Dioxide, SiO2)
Polished amber-colored translucent stone, likely citrine or yellow chalcedony
Most consistent with quartz (SiO₂), potentially citrine; translucent yellow chalcedony is another possibility
Note: Item is not a geological specimen
Homo sapiens (Dermal Appendage: Pilus)
Fossilized Coral (Petrified Coral)
Lithostrotionella (example genus) / Scleractinia
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Amber (possibly copal)
Fossilized plant resin; amber is organic resin, commonly dominated by polymerized terpenoids
Chert (Flint)
Silicon Dioxide (SiO2)
Amber
Succinited (fossilized tree resin)
Honey calcite
Calcite (CaCO₃), likely iron-stained honey/orange variety
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Polished amber-like organic gemstone
Likely amber (fossilized plant resin), possibly copal or brown chalcedony; exact identification requires testing
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Opalite
Synthetic Opalised Glass
Obsidian
Volcanic Glass (Amorphous Silica)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
Banded Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
Tumbled brown jasper (likely common jasper or chert)
Microcrystalline quartz, SiO₂, chiefly chalcedony/quartz with iron-oxide impurities
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite/Sepiolite inclusions
Banded Agate (Dyed)
SiO2 (Silicon Dioxide / Microcrystalline Quartz)
Quartz and Limestone Grouping
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions
Obsidian
Obsidian (Volcanic Glass, SiO2)
Bauxite
Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Amber
Fossilized plant resin; chiefly an organic polymer (succinite), not a crystalline mineral
Tumbled amber
Fossilized plant resin; commonly succinite (organic polymerized resin)