Banded Chert (Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Mineral Like Biological Tissue
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Learn about Mineral Like Biological Tissue in the encyclopedia
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Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Aragonite
Aragonite (Calcium Carbonate - CaCO3)
mineral
Shungite
Shungite (Non-crystalline carbon, C)
mineral
Polished fossiliferous agate
Chalcedony (microcrystalline SiO₂), likely containing fossil coral or stromatoporoid structures
sedimentary
Chert (likely Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Green Turban Shell (Polished)
Turbo marmoratus (Aragonite/Calcite)
mineral
Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Conglomerate with Fossilized Shark Teeth
Clastic sedimentary rock (Conglomerate) containing Elasmobranchii remains
sedimentary
Quartz with Pyrite and Lichen
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
mineral
Small marine shell fragment
Calcareous shell, primarily calcium carbonate (aragonite or calcite); exact taxon indeterminate
fossil
Fossilized Gastropod Shell
Class Gastropoda (Fossil)
sedimentary
Natural freshwater pearls
Pearl (nacreous calcium carbonate; chiefly aragonite, CaCO₃)
gemstone
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
mineraloid
Chert / Chalcedony Nodule
Silicon Dioxide (SiO2)
sedimentary
Fossil bivalve shell
Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features
fossil
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin
Organic Mineraloid
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
Amber
Succiniferous organic material (Succinite)
fossil
Banded Chert or Mudstone
Chert (Silicon dioxide, SiO2) or Mudstone
sedimentary
Gastropod shell fragment
Calcareous mollusk shell; primarily aragonite or calcite (CaCO₃)
fossil
Fossil bone fragment (likely vertebrate bone)
Fossilized vertebrate bone; exact taxon indeterminate from the photograph
fossil
Shark Tooth Fossil
Otodus obliquus (or similar prehistoric lamniform shark tooth)
fossil
Fossilized coral fragment
Fossil scleractinian coral; commonly calcite/aragonite replaced by calcite (CaCO₃)
fossil
Amber
Fossilized Resin (C10H16O)
mineral
Likely fossiliferous limestone fragment
Calcareous fossil assemblage, chiefly calcium carbonate (CaCO₃), possibly crinoid, bivalve, or bryozoan material in limestone
fossil
Hag Stone (Sandstone with Boreholes)
Bored Sandstone (Sedimentary rock with lithophaga-style borings)
sedimentary
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Geode with Quartz and Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Fossiliferous limestone, possibly coral-bearing
Calcitic limestone (mostly CaCO₃; fossil fragments may include ancient colonial coral or shell material)
sedimentary
Polished fossiliferous limestone
Bioclastic limestone, likely containing a solitary rugose coral or shell fossil (identification uncertain from image)
fossil
Chert / Flint (with Iron Staining)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
sedimentary
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Weathered flint or chert fragment
Microcrystalline quartz (SiO₂), likely chert/flint
sedimentary
Mosasaur Tooth Fossil
Mosasauridae (likely Prognathodon or Mosasaurus)
fossil
Amber
Succinite (approximate formula C10H16O)
mineraloid
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Jasper / Flint variant)
Microcrystalline Quartz (SiO2)
sedimentary