Petrified Wood
Silicified Wood (SiO2 permineralization)
sedimentary
Category
Organic Mineral
Browse organic mineral specimens identified by the Rock Identifier community.
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Fossiliferous Limestone containing a Brachiopod or Mollusk Impression
Biogenic Sedimentary Rock / Fossiliferous Limestone
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Precious Red Coral
Corallium rubrum / Corallium japonicum
mineral (organic gemstone)
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
sedimentary
Chert
Chert (SiO2)
sedimentary
Chert / Flint
Chert (Silicon Dioxide, SiO2)
sedimentary
Chert (Limestone-based)
Silicon dioxide (SiO2)
sedimentary
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Petrified Wood
Silicified wood (Quartz / Chalcedony replacement of organic cellulose)
fossil
Herkimer Diamond (Quartz with Carbon Inclusions)
Silicon Dioxide (SiO2) with Anthraxolite inclusions
mineral
Pyrite
Pyrite (Iron sulfide, FeS₂)
Mineral
Shale
Shale (clay-sized silicate minerals)
sedimentary
Calcareous Tufa (or Travertine)
Calcium Carbonate (CaCO3)
sedimentary
Sand Tiger Shark Tooth
Carcharias taurus (fossilized)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Chert (Green Chert/Jasper)
Chert (primarily Microcrystalline Quartz, SiO2)
sedimentary
Ammonite Fossil (Small Pyritized or Calcitized Internal Mold)
Ammonoidea
sedimentary
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Favosites Fossil (Honeycomb Coral)
Favosites (Extinct genus of Tabulate Coral)
sedimentary
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Mammoth or Mastodon Tooth Fossil
Proboscidea tooth (Mammuthus or Mammut)
fossil
Fossil Shark Tooth
Chondrichthyes (Class)
fossil
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Chert / River Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint variation)
Chert (SiO2)
sedimentary
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Mineral (Organic)
Fossil-bearing sedimentary rock, possibly fossil wood or bone
Indeterminate silicified/carbonate fossil in sandstone or mudstone
fossil
Fossilized Horse Tooth
Equus sp. (fossilized molar)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Chert (Flint) with Iron Staining
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
sedimentary