Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Category
Organic Gemstone (Not A Rock Or Mineral)
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral) in the encyclopedia
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Sandstone Concretion
Sedimentary Clastic Rock (Silicate-rich)
sedimentary
Fossilized Brachiopod
Brachiopoda (Phylum)
fossil
Quartz
Silicon Dioxide (SiO2)
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Amber
Succinite (Formula: C10H16O)
mineral
Coquina / Shelly Sandstone
Calcareous Sandstone / Coquina
sedimentary
Chert (Arrowhead/Artifact Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Moonstone
Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8
mineral
Chert Nodule / Ironstone Concretion
Microcrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Fossilized coral (likely honeycomb or branching coral)
Fossil coral; probable Scleractinia or Tabulata, composition mainly microcrystalline CaCO₃
fossil
Cobaltoan Calcite / Pink Dolomite (Possible)
Cobaltoan Calcite: (Ca,Co)CO3; Pink Dolomite (or Thulite): CaMg(CO3)2 or Mn-Dolomite / (Thulite: Mn2+3Al2(Si2O7)(SiO4)O(OH))
Mineral / Rock (depending on purity)
Shark Tooth Fossil
Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)
fossil
River Cobble (Sandstone)
Arenite (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Fossilized Bone
Petrified Bone (Fluorapatite / Calcium Phosphate replacement)
fossil
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
mineral
Seashell Fossil
Gastropoda fossil
fossil
Black Shale
Argillaceous Chert/Shale
sedimentary
Weathered River Rock (likely Chert or Basalt with algae)
Silicon dioxide (SiO2) with organic biofilm
sedimentary
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Jasper
Silicon dioxide (SiO2)
sedimentary
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Mineral
Sea Shell (Mollusk Shell)
Calcium Carbonate (Aragonite/Calcite)
fossil
Amber
Succinite (fossilized resin, C10H16O)
mineral
Quartz (Orange/Pink variety)
Silicon Dioxide (SiO2)
mineral
Purple Chalcedony
Silicon Dioxide (SiO2)
mineral
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
sedimentary
Spessartine Garnet in Quartz/Feldspar Pegmatite
Spessartine (Mn3Al2(SiO4)3) in Quartz (SiO2) and Feldspar
Mineral in Igneous Rock
Starfish Fossil
Asteroidea fossil
fossil
Coprolite
Fossilized Feces
fossil
Moss Agate (Crescent Moon Shape)
Silicon Dioxide (SiO2) with iron/manganese inclusions
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH)
mineral
Siltstone with Fossil Cast
Sedimentary Rock (Siltstone / Fine-grained Sandstone)
sedimentary
Shale (or Slate / Coal / Jet)
Laminated fine-grained sedimentary rock (predominantly clay minerals)
sedimentary
Pearl (Pendant)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
gemstone