Sea Shell (Mollusk Shell)
Calcium Carbonate (Aragonite/Calcite)
fossil
Category
Organic Gemstone
Browse organic gemstone specimens identified by the Rock Identifier community.
Learn about Organic Gemstone in the encyclopedia
View all →
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Amber
Succinates (Organic Fossilized Resin)
mineral
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
mineral
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Amber
Succinite (organic fossilized resin)
mineraloid
Amber
Amber (Amorphous Organic Hydrocarbon)
mineral
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Sedimentary
Amber
Succinite (fossilized resin)
mineral
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
sedimentary
Likely bituminous coal
Coal, predominantly carbon-rich organic matter with variable maceral and mineral content
sedimentary
Fossilized Shark Tooth
Selachimorpha fossil
fossil
Fossiliferous Limestone
Fossiliferous Limestone
sedimentary
Sedimentary Rock (Limestone or Siltstone pebble)
Sedimentary rock fragment
sedimentary
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
sedimentary
Seashell (Cone Snail Shell)
Conus sp. (Calcium Carbonate, CaCO3)
fossil
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
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
Succinates
mineraloid
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Quartz pebble or seed/crumb
SiO2 (if quartz)
mineral
Fossiliferous Limestone
Calcite (CaCO3) matrix with biogenic fragments
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (containing bioclasts)
sedimentary
Glauconite (Greensand)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Fossiliferous Limestone
Calcium carbonate matrix with macrofossils (CaCO3)
fossil
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with marine fossils
fossil
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
sedimentary
Petrified Wood
Petrified Wood (Silicified Wood)
fossil
Amber
Succinite (Fossilized Tree Resin)
fossil
Brown translucent mineral fragment, possibly iron-stained quartz or amber
Uncertain; likely quartz (SiO₂) with iron-oxide staining, though amber (fossilized resin) is possible
mineral
Fossilized bone fragment
Fossil bone, composed chiefly of carbonate-fluorapatite (bioapatite)
fossil
Chert Concretion
Microcrystalline Quartz (SiO2) in Carbonate Matrix
sedimentary
Amber
Succinate (Fossilized Resin)
mineral
White limestone or chalky carbonate rock
Calcite-rich limestone; possibly chalk (CaCO₃)
sedimentary