Coquina / Shelly Sandstone
Calcareous Sandstone / Coquina
sedimentary
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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Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Sandstone)
sedimentary
Agate (Moss or Dendritic Agate)
Chalcedony (Silicon Dioxide, SiO2)
mineral
Amber
Succinite (fossilized resin, C10H16O)
mineral
Fossil-bearing Sedimentary Rock
Sedimentum cum fossili
fossil
Jasper
Silicon dioxide (SiO2)
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Natural Pearl (appearing in a jewelry setting)
Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin
mineral
Fossilized Bone
Petrified Bone (Fluorapatite / Calcium Phosphate replacement)
fossil
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
sedimentary
Seashell Fossil
Gastropoda fossil
fossil
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Organic Gemstone (not a rock)
Siltstone with Fossil Cast
Sedimentary Rock (Siltstone / Fine-grained Sandstone)
sedimentary
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Chert with Quartz Vein
Silicon dioxide (SiO2)
sedimentary
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (Formula: C10H16O)
Mineraloid
Starfish Fossil
Asteroidea fossil
fossil
Yellow-brown translucent mineral fragment, likely citrine or amber
Quartz (SiO₂), if citrine; succinite (fossil resin), if amber
mineral
Orbicular granite (likely Rapakivi-type granite)
Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
sedimentary (matrix) / mineral (inclusion)
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)
mineral
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
mineral and glass
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
mineral
Black Shale
Argillaceous Chert/Shale
sedimentary
Limestone with Calcite Veining
Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Limestone Concretion (Botryoidal/Calcareous Nodules)
Calcium Carbonate Concretion (CaCO3)
sedimentary
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
fossil
Sandstone Concretion
Sedimentary Clastic Rock (Silicate-rich)
sedimentary
Quartz Vein Rock
Silicon dioxide (SiO2) within a host rock matrix
mineral
Dendritic jasper/chalcedony
Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites
mineral
Quartz and Limestone Grouping
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)
mineral
Chert (Jasper/Agate Peat)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Plume Agate
Cryptocrystalline Quartz (SiO2)
Mineral/Gemstone
Pearl
Nacre (primarily aragonite, CaCO₃, in an organic conchiolin matrix)
gemstone
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
sedimentary
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
mineral