Pyrite in Shale
Iron Disulfide (FeS2) in Sedimentary Shale
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Pyrite in Shale
Iron Disulfide (FeS2) in Sedimentary Shale
Petrified Wood
Silicified Wood (SiO2)
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin
Banded Chert
Microcrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite
Amber
Succinite
Fossilized Shark Teeth
Otodus sp. (Eocene Sand Tiger/Mackerel Shark)
Petrified Wood
Silicified Wood (primarily SiO2)
Fossilized Coral (Petoskey Stone or Rugose Coral)
Antophyllum (Hexagonaria) or Scleractinia (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint nodule)
Chert (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Pyrite (Pseudomorph)
Iron Sulfide (FeS2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Amber / Copal
Organic resin, C10H16O
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Coprolite
Fossilized Feces
Shark Tooth Fossil
Carcharodonta (order Lamniformes), likely Carcharias spp.
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Calligraphy Stone
Fossiliferous Limestone (containing Hematite and Shells)
Petrified Wood
Silicified Wood (primarily SiO2)
Jasper
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (often called Flint)
Microcrystalline to cryptocrystalline quartz (SiO2)
Fossilized Shark Tooth
Carcharocles sp. (likely Lemon or Sand Tiger)
Sunstone
Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Amethyst
Silicon dioxide (SiO2) with iron impurities
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Malachite with Chrysocolla
Copper carbonate hydroxide (Cu2CO3(OH)2) and Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Petrified Wood
Silicified Wood (primarily Silicon Dioxide, SiO2)
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
Chert (Flint Pebbles)
Microcrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Kidney Stone
Calcium Oxalate (CaC2O4), Uric Acid, or Struvite
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Prehnite
Ca2Al2Si3O10(OH)2
Citrine Quartz
Silicon Dioxide (SiO2)