Chert Concretion / Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Category
Organic Gemstone
Browse organic gemstone specimens identified by the Rock Identifier community.
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Amber
Succinite
mineral
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Amber
Succinates (Fossilized Resin)
mineral
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
sedimentary
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
fossil
Amber in Matrix
Succinite (Carbon-based organic polymer)
Organic (Sedimentary context)
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
sedimentary
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
sedimentary
Knightia Fossil in Limestone
Knightia eocaena in micritic limestone
sedimentary
Glauconitic Sandstone
Glauconitic Quartz Arenite (with K,Mg,Fe,Al silicate hydroxide)
sedimentary
Glauconitic Sanstone (Glauconite)
Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
fossil
Coquina (Fossiliferous Limestone)
Coquina (Organic Clastic Limestone)
sedimentary
Amber
Succinite (Organic Mineraloid) - C10H16O
mineral
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Amber
Succinite (fossilized tree resin)
fossil
Chert (and Fossilized Brachiopod shell)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Tumbled chalcedony (likely moss or dendritic agate)
Microcrystalline quartz, SiO₂, with iron-oxide inclusions
mineral
Limestone Pebble
Sedimentary carbonate rock (CaCO3)
sedimentary
Amber
Succinite (fossilized tree resin)
mineral
Moss Agate
Silicon dioxide (SiO2) with inclusions
Mineral
Fossil Bivalve / Ostreid Shell (Hag Stone / Perforated Pebble)
Phylum Mollusca, Class Bivalvia
fossil
Coal (Bituminous or Anthracite)
Carbonaceous sedimentary rock (primarily Carbon, C)
sedimentary
Limestone with Fossil Inclusion
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Megalodon Shark Tooth (Partial Fossil)
Otodus megalodon (fossilized in Calcium Phosphate/Apatite)
Mineral/Fossil
Fossiliferous Limestone
Limestone (Calcium Carbonate - CaCO3)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Gemstone Ring
N/A - Set piece of jewelry, likely Amethyst or Garnet with Diamond or CZ
gemstone
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Bone Fragment
Vertebrate Fossil
fossil
Shark Tooth Fossil
Carcharhiniformes or Lamniformes (order level fossil)
fossil
Petrified Wood
Silicified wood (SiO2)
fossil
Fossil Shark Tooth (Sand Tiger or Mackerel Shark)
Carcharias sp. or Otodus sp. replaced by Hydroxylapatite/Calcium Carbonate
sedimentary