Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
Chert (Field Stone)
Microcrystalline Quartz (SiO2)
Pink Coral
Corallium rubrum (organic gemstone)
Coal (Bituminous)
Organic sedimentary rock primarily consisting of carbon (C)
Jasper
Microcrystalline Quartz (SiO2)
Travertine
Tufa limestone (CaCO3)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Red coral cabochon (likely dyed or reconstructed coral)
Corallium rubrum or other calcareous coral; chiefly aragonite (CaCO₃)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcareous sedimentary rock (CaCO3)
Fossilized tooth, likely a mammalian tooth fragment
Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth
Banded Chert (likely Flint or Jasper variety)
Silicon Dioxide (SiO2)
Chert (with Drusy Quartz Pocket)
Silicon Dioxide (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Amber
Resinite / Fossilized Tree Resin
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Agate (Moss or Green Agate)
Silicon Dioxide (SiO2)
Vuggy Limestone
Carbonate Sedimentary Rock with Vuggy Porosity (CaCO3)
Petrified Wood
Silicified wood / Permineralized wood (SiO2)
Fossiliferous Limestone
Carbonate Sedimentary Rock (primarily CaCO3)
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Note: Item is not a geological specimen
n/a
Chert (Jasper)
Silicon Dioxide (SiO2)
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
Chert Nodule
Chert (Cryptocrystalline variety of Quartz, SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Agate mix)
Microcrystalline Quartz (SiO2)
Chert (Commonly called Jasper or Flint)
Chert (SiO2)
Moss Agate with Jasper
Chalcedony (SiO2 with inclusions)
Shale (possibly Carbonaceous or Oil Shale)
Argillaceous Sedimentary Rock
Petrified Wood
Silicified Wood (SiO2)
Limestone
Calcareous sedimentary rock (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Fossil Shell (Brachiopod or Mollusk)
Phylum Brachiopoda or Class Bivalvia (e.g., Mucrospirifer or similar genus)
Fossilized coral (likely honeycomb or branching coral)
Fossil coral; probable Scleractinia or Tabulata, composition mainly microcrystalline CaCO₃
Polished banded agate (likely picture jasper or petrified wood)
Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions