Rock Identifier

Category

Biogenic Material

Browse biogenic material specimens identified by the Rock Identifier community.

Learn about Biogenic Material in the encyclopedia

Peat

Diatomite

Dunite

Limonite

Shell Opal

Madagascar Opal

Lavender Obsidian

Electric Blue Obsidian

Orange Obsidian

Diamond

Metarhyolite

Rhodochrosite

Polished brown flint/chert nodule (Microcrystalline quartz (SiO₂), commonly called flint or chert) — sedimentary

Polished brown flint/chert nodule

Microcrystalline quartz (SiO₂), commonly called flint or chert

Chert or microcrystalline quartz fragment (Chert; cryptocrystalline SiO₂, possibly chalcedony-rich) — sedimentary

Chert or microcrystalline quartz fragment

Chert; cryptocrystalline SiO₂, possibly chalcedony-rich

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

Chert (Nodule)

Microcrystalline Silica (SiO2)

Mother of Pearl (Nacre) (Aragonite with Conchiolin (CaCO3)) — mineral

Mother of Pearl (Nacre)

Aragonite with Conchiolin (CaCO3)

Chert (likely brown flint) (Microcrystalline quartz, SiO₂ (chalcedonic quartz aggregate)) — sedimentary

Chert (likely brown flint)

Microcrystalline quartz, SiO₂ (chalcedonic quartz aggregate)

Tumbled yellow-brown stone, likely chert or jasper (Microcrystalline quartz (SiO₂), possibly iron-stained chert/jasper) — sedimentary

Tumbled yellow-brown stone, likely chert or jasper

Microcrystalline quartz (SiO₂), possibly iron-stained chert/jasper

Chert or flint (weathered brown variety) (Microcrystalline quartz, SiO₂ (chalcedonic quartz)) — sedimentary

Chert or flint (weathered brown variety)

Microcrystalline quartz, SiO₂ (chalcedonic quartz)

Tumbled dark flint/chert (Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide impurities) — sedimentary

Tumbled dark flint/chert

Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide impurities

Coquina (Biogenic Limestone (Calcite/Aragonite base, CaCO3)) — sedimentary

Coquina

Biogenic Limestone (Calcite/Aragonite base, CaCO3)

Beaded mineral/crystal jewelry (likely turquoise and coral accents) (Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials) — gemstone

Beaded mineral/crystal jewelry (likely turquoise and coral accents)

Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials

Coquina (Biogenic Limestone (Coquina)) — sedimentary

Coquina

Biogenic Limestone (Coquina)

Fossiliferous Limestone (Biogenic Sedimentary Rock) — sedimentary

Fossiliferous Limestone

Biogenic Sedimentary Rock

Coquina (Biogenic Limestone (CaCO3)) — sedimentary

Coquina

Biogenic Limestone (CaCO3)

Coquina / Shelly Limestone (Coquina (Biogenic Limestone)) — sedimentary

Coquina / Shelly Limestone

Coquina (Biogenic Limestone)

Pearl (Biogenic CaCO3 (Aragonite)) — mineral

Pearl

Biogenic CaCO3 (Aragonite)

Fossiliferous Limestone / Fossil Fragment (Calcium Carbonate (CaCO3) with indeterminate biogenic remains) — fossil

Fossiliferous Limestone / Fossil Fragment

Calcium Carbonate (CaCO3) with indeterminate biogenic remains

Iron-stained chert or siliceous mudstone (Microcrystalline quartz (SiO₂), likely chert with hematite/goethite staining) — sedimentary

Iron-stained chert or siliceous mudstone

Microcrystalline quartz (SiO₂), likely chert with hematite/goethite staining

Weathered chert or silicified limestone nodule (Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃)) — sedimentary

Weathered chert or silicified limestone nodule

Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃)

Water and Silt (Sedimentary Environment) (Suspended Sediment / H2O (dihydrogen monoxide)) — sedimentary

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

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

Chert (Pink/Red variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded chert or flint (Microcrystalline quartz (SiO₂), likely with iron-oxide and dark organic/mineral impurities) — sedimentary

Banded chert or flint

Microcrystalline quartz (SiO₂), likely with iron-oxide and dark organic/mineral impurities

Chalk / Sedimentary Limestone (Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock) — sedimentary

Chalk / Sedimentary Limestone

Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock

Chert / Flint (with Jasper inclusions) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Flint (with Jasper inclusions)

Microcrystalline Quartz (SiO2)

Fossiliferous limestone, likely coral or shell-rich limestone (Biogenic calcite (CaCO₃), commonly limestone containing fossil coral or mollusks) — fossil

Fossiliferous limestone, likely coral or shell-rich limestone

Biogenic calcite (CaCO₃), commonly limestone containing fossil coral or mollusks

Fossilized Shell Fragment / Mother of Pearl (Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral) — fossil

Fossilized Shell Fragment / Mother of Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral

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

Chert (Flint Nodule)

Microcrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Brown flint or chert pebble (Microcrystalline quartz (SiO₂), commonly with iron-oxide staining) — sedimentary

Brown flint or chert pebble

Microcrystalline quartz (SiO₂), commonly with iron-oxide staining

Pearl (Biogenic) (Nacre / Calcium Carbonate (CaCO3)) — mineral

Pearl (Biogenic)

Nacre / Calcium Carbonate (CaCO3)

Chert (and associated Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and associated Flint)

Silicon Dioxide (SiO2)

Chert / Flint (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert / Flint

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Nodular Chert) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Nodular Chert)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Fossiliferous Limestone (Biogenic Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Limestone (CaCO3)

Fossiliferous Limestone (Biogenic Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Limestone (CaCO3)

Fossiliferous Limestone (Coquina / Shell Limestone) (Biogenic Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (CaCO3)

Worn quartz-rich pebble (Likely microcrystalline quartz (SiO₂), possibly a weathered chert or milky quartz fragment) — mineral

Worn quartz-rich pebble

Likely microcrystalline quartz (SiO₂), possibly a weathered chert or milky quartz fragment

Fossiliferous Limestone / Fossil Fragment (Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)) — fossil

Fossiliferous Limestone / Fossil Fragment

Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)

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

Flint (Chert Nodules)

SiO2 (Cryptocrystalline Quartz)

Precious Coral (Corallium rubrum (Calcium Carbonate, CaCO3)) — mineral

Precious Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Seashell (Calcium Carbonate) (Calcium Carbonate (CaCO3)) — mineral

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)

Likely fossilized shell or carbonate concretion (Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)) — fossil

Likely fossilized shell or carbonate concretion

Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)

Tumbled brown chert or jasper pebble (Microcrystalline quartz (SiO₂), likely chert/jasper) — sedimentary

Tumbled brown chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper