Pearl necklace
Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)
gemstone
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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Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
mineral/sedimentary
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Megalodon Shark Tooth (Partial Fossil)
Otodus megalodon (fossilized in Calcium Phosphate/Apatite)
Mineral/Fossil
Fossilized Vertebra
Chordata fossil (Vertebra)
fossil
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amber
Succinite (formula varies, primarily C10H16O)
Mineraloid (Organic)
Pearl (as a biogenic mineral/gemstone)
Calcium Carbonate (mostly Aragonite), CaCO3
mineral
Obsidian
Volcanic glass (Mainly SiO2)
igneous
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Pearl (Pendant)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
gemstone
Polished fossilized wood
Silicified wood (petrified wood), commonly quartz/chalcedony replacing wood
fossil
Blue Apatite
Fluoroapatite (Ca5(PO4)3F)
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin, CaCO3
gemstone
Fossil bivalve shell
Likely an internal mold or mineralized shell of a brachiopod or small bivalve; exact taxonomy requires locality and diagnostic details
fossil
Fossilized bone or tooth fragment (indeterminate vertebrate fossil)
Mineralized vertebrate skeletal material; commonly apatite, Ca₅(PO₄)₃(F,Cl,OH), partly replaced by silica or calcite
fossil
Dendritic Agate or Manganese Nodule in Chert/Limestone
Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions
sedimentary
Fossilized Shark Tooth
Selachii (Elasmobranchii subclass)
fossil
Botryoidal calcite (likely calcite concretion)
Calcite, calcium carbonate (CaCO₃)
mineral
Fossilized Shark Tooth
Elasmobranchii fossil (likely Odontaspididae family)
sedimentary
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Sandstone or Quartzite with algae
Unknown specific, largely SiO2 with biological growth
sedimentary or metamorphic
Fossilized wood or bone fragment
Indeterminate permineralized organic fossil; possibly silicified wood or fossil bone
fossil
Pearl
Calcium carbonate (CaCO3) in the form of Aragonite or Calcite
mineral
Amber
Fossilized tree resin (Amorphous organic polymer)
gemstone
Fossilized tooth, likely a mammalian tooth fragment
Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth
fossil
Fossilized Bone
Fossilized Vertebrate Bone (Per mineralized)
fossil
Pearl (in a decorative hair comb setting)
Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin
Organic Mineraloid
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amber
Succinite (Fossilized Tree Resin)
mineraloid
Chert
Chert (SiO2)
sedimentary
Fossil bone fragment
Fossilized vertebrate bone; exact taxon undetermined
fossil
Polished petrified wood
Silicified wood, chiefly microcrystalline quartz (SiO₂), often with chalcedony and iron oxides
fossil
Fossilized Shark Tooth
Fossil Chondrichthyes (various genera such as Carcharias or Odontaspis)
sedimentary
Garnet
Almandine-Pyrope group, X3Y2(SiO4)3
mineral
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
metamorphic
Chert (Arrowhead Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Pearl
Calcium carbonate (CaCO3) - Aragonite/Calcite variety
mineral