Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified Wood (SiO2)
sedimentary
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2) with iridescent tarnish
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Sedimentary / Metamorphic
Red Jasper Concretion
Cryptocrystalline Quartz (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
Mineral / Sedimentary
Ferruginous Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Pink Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O)
mineral
Lake Superior Agate
Silicon Dioxide (Cryptocrystalline Quartz), SiO2
mineral
Fossiliferous Shale
Laminated Mudrock with plant fossils
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
mineral
Fluorite with Quartz
Fluorite (CaF2) and Quartz (SiO2)
mineral
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
metamorphic
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
sedimentary
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Malachite in Matrix
Copper Carbonate Hydroxide (Cu2CO3(OH)2)
mineral
Ferruginous Sandstone with Concretion
Sandstone (SiO2 dominated with Fe2O3 cement)
sedimentary
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Mineral
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
mineral
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Shark Tooth Fossil
Otodus sp. (possibly Cretalamna)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Mineral/Fossil (Sedimentary context)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Garnet
Pyrope or Almandine (X3Y2(SiO4)3)
mineral
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
tektite
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Mineraloid
Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)
Mixed Silicates and Sulfides (SiO2, FeS2)
mineral
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Chalcedony variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
sedimentary