Rock Identifier

Category

Sedimentary (Biogenic)

Browse sedimentary (biogenic) specimens identified by the Rock Identifier community.

Limonite Concretion (Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O) — sedimentary

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

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

Hematite

Iron(III) oxide (Fe2O3)

Banded Quartzite (Quartzite (SiO2 with impurities)) — metamorphic

Banded Quartzite

Quartzite (SiO2 with impurities)

Leopard Skin Jasper (Rhyolite (Silicon Dioxide with impurities), SiO2) — igneous

Leopard Skin Jasper

Rhyolite (Silicon Dioxide with impurities), SiO2

Dalmatian Stone (Dalmatian Jasper) (Peralkaline Quartz-Feldspar Rock with Arfvedsonite) — igneous

Dalmatian Stone (Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Granite (Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)) — igneous

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)

Limestone (Cliff Formation) (Limestone (predominantly CaCO3 as calcite)) — Sedimentary

Limestone (Cliff Formation)

Limestone (predominantly CaCO3 as calcite)

Banded Iron Formation (BIF) (Banded Iron Formation) — Sedimentary

Banded Iron Formation (BIF)

Banded Iron Formation

Sandstone (Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)) — Sedimentary

Sandstone

Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment) (Quartz (SiO₂)) — Mineral

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Gneiss with Quartz Vein (Gneiss containing Quartz (SiO2) filler) — metamorphic

Gneiss with Quartz Vein

Gneiss containing Quartz (SiO2) filler

Druzy Quartz (on Chalcedony/Agate base) (Silicon Dioxide (SiO2)) — mineral

Druzy Quartz (on Chalcedony/Agate base)

Silicon Dioxide (SiO2)

Optical Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Optical Calcite

Calcite (Calcium Carbonate, CaCO3)

Red Jasper (Silicon Dioxide (SiO2) with Hematite impurities) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

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

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

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

Chert (Flint variety)

Chert (SiO2)

Carnelian (Red Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2)

Jasper with Epidote (Silicon Dioxide (SiO2) with Calcium Aluminum Iron Sorosilicate [Ca2Al2Fe3+Si3O12(OH)]) — sedimentary/metamorphic

Jasper with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Sorosilicate [Ca2Al2Fe3+Si3O12(OH)]

sedimentary/metamorphic

Chert (and/or Flint) (Silicon dioxide (SiO2)) — sedimentary

Chert (and/or Flint)

Silicon dioxide (SiO2)

Quartzite (Quartzite (chiefly SiO2)) — metamorphic

Quartzite

Quartzite (chiefly SiO2)

Chalcedony (Agate/Quartz variety) (Cryptocrystalline Quartz (SiO2)) — mineral

Chalcedony (Agate/Quartz variety)

Cryptocrystalline Quartz (SiO2)

Carnelian (Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

Yellow Agate (Silicon Dioxide (SiO2) - variety of Chalcedony) — mineral

Yellow Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Clear Quartz Crystal Cluster (Silicon Dioxide (SiO2)) — mineral

Clear Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Quartz (Milky/Clear Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Clear Quartz)

Silicon Dioxide (SiO2)

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

Druzy Quartz on Limestone

Silicon Dioxide (SiO2)

Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Potassium Feldspar (Orthoclase) (KAlSi3O8) — mineral

Potassium Feldspar (Orthoclase)

KAlSi3O8

Fossilized Coral (Coquina/Limestone) (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

Honey Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Red Jasper (Polished) (Silicon Dioxide (SiO2) with Hematite inclusions) — sedimentary

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Red Jasper (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

White Agate (resembling Bone Chalcedony) (Cryptocrystalline Quartz (SiO2)) — mineral

White Agate (resembling Bone Chalcedony)

Cryptocrystalline Quartz (SiO2)

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

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Chalcedony (Carnelian/Agate variety) (Silicon Dioxide (SiO2) with trace hematite/iron impurities) — mineral

Chalcedony (Carnelian/Agate variety)

Silicon Dioxide (SiO2) with trace hematite/iron impurities

Optical Calcite (Iceland Spar) (Calcite (Calcium Carbonate, CaCO3)) — mineral

Optical Calcite (Iceland Spar)

Calcite (Calcium Carbonate, CaCO3)

Chert / Flint (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Chalcedony (Agate/Carnelian variant) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Carnelian variant)

Silicon Dioxide (SiO2)

Blue Chalcedony (Chalcedony (cryptocrystalline Silicon Dioxide - SiO2)) — mineral

Blue Chalcedony

Chalcedony (cryptocrystalline Silicon Dioxide - SiO2)

Cinnabar in Matrix (Cinnabar (Mercury(II) sulfide, HgS)) — mineral

Cinnabar in Matrix

Cinnabar (Mercury(II) sulfide, HgS)