Fossiliferous limestone
Bioclastic carbonate rock; predominantly calcite (CaCO₃)
sedimentary
Category
Organic Structure (Not A Rock)
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
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Chert Nodules or Concretion
Cryptocrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock
sedimentary
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
sedimentary
Pink granite
Coarse-grained felsic intrusive rock, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende
igneous
Coal (Bituminous or Anthracite)
Carbonaceous sedimentary rock (primarily Carbon, C)
sedimentary
Fossilized Bone
Petrified Bone (Fluorapatite / Calcium Phosphate replacement)
fossil
Sandstone
Arenite
sedimentary
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
sedimentary
Fossiliferous Limestone
Limestone with embedded fossil cross-section
sedimentary
Sandstone
Arenite
sedimentary
Polished brecciated jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide coloration and possible breccia fragments
mineral
Lapis Lazuli (polished cabochon)
Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)
metamorphic
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
sedimentary
Limestone with Lichen/Moss
Calcium Carbonate (CaCO3)
sedimentary
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
sedimentary
Shale
Fissile Mudstone (Shale)
sedimentary
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Agatized Petrified Wood
Silicon Dioxide (SiO2) - Chalcedony pseudomorph after Wood
metamorphic
River Pebble (Siltstone/Mudstone)
Clastic sedimentary rock
sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)
sedimentary
Shark Tooth Fossil
Chondrichthyes (class) fossilized tooth
fossil
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Shale
Shale (comprised mostly of clay minerals and quartz)
sedimentary
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
sedimentary
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Limestone with Lichen
Calcium Carbonate (CaCO3) with Endolithic/Epilithic Lichen
sedimentary
Lapis Lazuli
Na8(Al6Si6O24)S2 (composed primarily of Lazurite, Calcite, and Pyrite)
metamorphic
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Non-geological
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Chert (Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
sedimentary
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
sedimentary
Lapis lazuli
Lapis lazuli; primarily lazurite (Na₃Ca(Si₃Al₃)O₁₂S), with calcite and pyrite
metamorphic
Note: This is a Man-Made Object (Costume/Prop Patch)
Synthetic fiber and pigments (Cellulose/Plastic-based composite)
Non-geological
Bauxite
Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
sedimentary
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Non-geological / Synthetic
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
sedimentary
Sandstone
Arenite
sedimentary
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
sedimentary