Rock Identifier

Category

Sedimentary (Fossilized Organic Matter)

Browse sedimentary (fossilized organic matter) specimens identified by the Rock Identifier community.

Carnelian (Carnelian (SiO2 with Iron Oxide impurities)) — mineral

Carnelian

Carnelian (SiO2 with Iron Oxide impurities)

Banded Slate or Siltstone with Quartz/Calcite Veins (Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)) — metamorphic

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Quartzite River Stone (Quartzite (primarily SiO2)) — metamorphic

Quartzite River Stone

Quartzite (primarily SiO2)

Precious Opal (Hydrated amorphous silica (SiO2·nH2O)) — mineral

Precious Opal

Hydrated amorphous silica (SiO2·nH2O)

Hematite / Goethite (Iron Ore) (Iron Oxide (Fe2O3 / FeO(OH))) — mineral

Hematite / Goethite (Iron Ore)

Iron Oxide (Fe2O3 / FeO(OH))

Rhodochrosite (Manganese carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese carbonate (MnCO3)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Yellow Quartzite or Yellow Jasper (Quartzite (primarily SiO2 with Iron oxide staining)) — metamorphic

Yellow Quartzite or Yellow Jasper

Quartzite (primarily SiO2 with Iron oxide staining)

Quartzite River Rock (Quartzite (primarily SiO2)) — metamorphic

Quartzite River Rock

Quartzite (primarily SiO2)

Quartz (Druzy) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy)

Silicon Dioxide (SiO2)

Quartz Druze on Matrix (Silicon Dioxide (SiO2)) — mineral

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Limonite (Hydrated Iron Oxide / Bog Iron) (FeO(OH)·nH2O) — Mineral (Sedimentary context)

Limonite (Hydrated Iron Oxide / Bog Iron)

FeO(OH)·nH2O

Mineral (Sedimentary context)

Chert (Nodule) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Gneiss (Stream-worn Cobble) (Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)) — metamorphic

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

Crushed Limestone (Calcium Carbonate (CaCO3)) — Sedimentary

Crushed Limestone

Calcium Carbonate (CaCO3)

Chert (Tan/Yellow variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Tan/Yellow variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Red Sandstone (Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)) — sedimentary

Red Sandstone

Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)

Crinoid Fossil in Limestone (Class Crinoidea in Carbonate Matrix (CaCO3)) — sedimentary

Crinoid Fossil in Limestone

Class Crinoidea in Carbonate Matrix (CaCO3)

Red Sandstone (Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)) — sedimentary

Red Sandstone

Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Chert (White Chert/Flint) (Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (White Chert/Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Siltstone (Siltstone (primarily SiO2 with Al2O3)) — sedimentary

Siltstone

Siltstone (primarily SiO2 with Al2O3)

Limonite (Ironstone Concretion) (Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)) — sedimentary

Limonite (Ironstone Concretion)

Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)

Chert (Jasper) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

Chert (Red Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Red Jasper)

Microcrystalline Quartz (SiO2)

Red Sandstone (Arenite (Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Chert (Pink/Red variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Pink/Red variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Siltstone (Siltstone) — sedimentary

Siltstone

Siltstone

Chert (or Flint) (SiO2 (predominantly microcrystalline quartz)) — Sedimentary

Chert (or Flint)

SiO2 (predominantly microcrystalline quartz)

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

Chalcedony on Matrix (Silicon Dioxide (SiO2)) — mineral

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Hematite (Hematite (Iron(III) oxide, Fe2O3)) — mineral

Hematite

Hematite (Iron(III) oxide, Fe2O3)

Banded Calcite (often sold as Caribbean Calcite or Mexican Onyx) (Calcium Carbonate (CaCO3)) — mineral

Banded Calcite (often sold as Caribbean Calcite or Mexican Onyx)

Calcium Carbonate (CaCO3)

Quartz (Smoky/Grey variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Tumbled Carnelian and Quartz Mix (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Chert (Jasper/Flint variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chalcedony (specifically Common Opal or Agate variant) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (specifically Common Opal or Agate variant)

Silicon Dioxide (SiO2)

Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Ironstone Concretion (Nutstone) (Ironstone (with High Limonite/Hematite Content)) — sedimentary

Ironstone Concretion (Nutstone)

Ironstone (with High Limonite/Hematite Content)