Rock Identifier

Category

Mineraloid (Organic)

Browse mineraloid (organic) specimens identified by the Rock Identifier community.

Chert (containing a small fossil) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (containing a small fossil)

Microcrystalline Quartz (SiO2)

Fossilized Solitary Rugose Coral (Order Rugosa (commonly Horn Coral)) — sedimentary

Fossilized Solitary Rugose Coral

Order Rugosa (commonly Horn Coral)

Banded Gneiss (Gneiss (pronounced 'nice')) — metamorphic

Banded Gneiss

Gneiss (pronounced 'nice')

Pearl (Calcium Carbonate (Aragonite) - CaCO3) — mineral

Pearl

Calcium Carbonate (Aragonite) - CaCO3

Brain Coral Fossil (Family Mussidae or Merulinidae (Order Scleractinia)) — sedimentary

Brain Coral Fossil

Family Mussidae or Merulinidae (Order Scleractinia)

Pearl (Calcium Carbonate (primarily Aragonite and Calcite), CaCO3) — mineral

Pearl

Calcium Carbonate (primarily Aragonite and Calcite), CaCO3

Gastropod Steinkern (Internal Mold Fossil) (Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix) — sedimentary

Gastropod Steinkern (Internal Mold Fossil)

Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix

Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Pearl (Aragonite (CaCO3) with Conchiolin) — mineral

Pearl

Aragonite (CaCO3) with Conchiolin

Horn Coral Fossil (Rugosa (Order Rugosa)) — sedimentary

Horn Coral Fossil

Rugosa (Order Rugosa)

Fossiliferous Limestone (Fossiliferous Calclutite / Bio-calcarenite (CaCO3)) — sedimentary

Fossiliferous Limestone

Fossiliferous Calclutite / Bio-calcarenite (CaCO3)

Coprolite (Coprolite) — sedimentary

Coprolite

Coprolite

Sandstone (with potential trace fossils) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with potential trace fossils)

Clastic sedimentary rock (primarily SiO2)

Fossilized Coral (Petoskey Stone / Favosites) (Favosites (extinct genus of tabulate coral)) — sedimentary

Fossilized Coral (Petoskey Stone / Favosites)

Favosites (extinct genus of tabulate coral)

Limestone Pebble (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone Pebble

Sedimentary Calcium Carbonate (CaCO3)

Yellow Calcite (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

Fossiliferous Limestone (with Coralline Inclusions) (Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (with Coralline Inclusions)

Calcium Carbonate (CaCO3)

Greenstone (Epidote/Chlorite-rich Metabasalt) (Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))) — metamorphic

Greenstone (Epidote/Chlorite-rich Metabasalt)

Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

Fossiliferous Limestone (Biogenic Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Calcium Carbonate (CaCO3)

Coral Fossil (Favosites) (Favosites (Extinct genus of tabulate corals)) — sedimentary

Coral Fossil (Favosites)

Favosites (Extinct genus of tabulate corals)

Bryozoan Fossil (Phylum Bryozoa (commonly known as 'moss animals')) — sedimentary

Bryozoan Fossil

Phylum Bryozoa (commonly known as 'moss animals')

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Banded Iron Formation (BIF) (Banded Iron Formation containing Hematite (Fe2O3) and Magnetite (Fe3O4)) — sedimentary

Banded Iron Formation (BIF)

Banded Iron Formation containing Hematite (Fe2O3) and Magnetite (Fe3O4)

Chert (Common Opal/Agate inclusion) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Common Opal/Agate inclusion)

Microcrystalline Quartz (SiO2)

Travertine (Tufa) (Chemical Sedimentary Limestone (CaCO3)) — sedimentary

Travertine (Tufa)

Chemical Sedimentary Limestone (CaCO3)

Limestone (Flagstone) (Fossiliferous Limestone (CaCO3)) — sedimentary

Limestone (Flagstone)

Fossiliferous Limestone (CaCO3)

Chalk (CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock) — Sedimentary

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Aragonite (Aragonite (Carbonate mineral), CaCO3) — mineral

Aragonite

Aragonite (Carbonate mineral), CaCO3

Chert Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Quartz (SiO2)

Piddock bored rock (Boring Stone) (Ichnofossil-bearing Limestone or Mudstone (trace fossils by Pholadidae)) — sedimentary

Piddock bored rock (Boring Stone)

Ichnofossil-bearing Limestone or Mudstone (trace fossils by Pholadidae)

Sandstone with Liesegang Rings (Arenite with secondary Iron oxide (Limonite/Goethite) precipitation) — sedimentary

Sandstone with Liesegang Rings

Arenite with secondary Iron oxide (Limonite/Goethite) precipitation

Fossiliferous Limestone (Crinoidal) (Bioclastic Limestone (predominantly CaCO3)) — sedimentary

Fossiliferous Limestone (Crinoidal)

Bioclastic Limestone (predominantly CaCO3)

Fossilized Coral (Petoskey-like or Favosites) (Anthozoa (Fossilized Coral)) — sedimentary

Fossilized Coral (Petoskey-like or Favosites)

Anthozoa (Fossilized Coral)

Chert (Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)) — Sedimentary

Chert

Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)

Fossiliferous Limestone (Calcium Carbonate (CaCO3) with Bioclastic Inclusions) — sedimentary

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Bioclastic Inclusions

Shale (Fissile Mudrock (Clay-rich Sedimentary Rock)) — sedimentary

Shale

Fissile Mudrock (Clay-rich Sedimentary Rock)

Sandstone (with Lichen) (Arenite (primarily SiO2)) — sedimentary

Sandstone (with Lichen)

Arenite (primarily SiO2)

Pearl (as a biogenic mineral/gemstone) (Calcium Carbonate (mostly Aragonite), CaCO3) — mineral

Pearl (as a biogenic mineral/gemstone)

Calcium Carbonate (mostly Aragonite), CaCO3

Shale (Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)) — sedimentary

Shale

Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)

Pumice (Pumice (Vesicular Rhyolite/Andesite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Shale with Siltstone layering (Sedimentary Clastic Rock (Mudstone/Shale)) — sedimentary

Shale with Siltstone layering

Sedimentary Clastic Rock (Mudstone/Shale)

Fossilized Favosites (Honeycomb Coral) (Favosites (Genus), Phylum Cnidaria, Class Anthozoa) — sedimentary

Fossilized Favosites (Honeycomb Coral)

Favosites (Genus), Phylum Cnidaria, Class Anthozoa