Rock Identifier

Category

Organic (Geological Relative)

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

Coral Fossil (Petrified Coral) (Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)) — sedimentary

Coral Fossil (Petrified Coral)

Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)

Limestone (Weathered) (Sedimentary carbonate rock, primarily calcium carbonate (CaCO3)) — sedimentary

Limestone (Weathered)

Sedimentary carbonate rock, primarily calcium carbonate (CaCO3)

Calcite (Calcite (Mineral; CaCO₃)) — Mineral

Calcite

Calcite (Mineral; CaCO₃)

Dark mafic igneous rock, likely basalt or gabbro (Basalt–gabbroic rock; mainly plagioclase feldspar and pyroxene, possibly olivine or magnetite) — igneous

Dark mafic igneous rock, likely basalt or gabbro

Basalt–gabbroic rock; mainly plagioclase feldspar and pyroxene, possibly olivine or magnetite

Slate (Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)) — metamorphic

Slate

Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)

Anthracite Coal (Anthracite (Carbon-based metamorphic rock, 86-97% C)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

Megalodon Shark Tooth (Otodus megalodon) — fossil

Megalodon Shark Tooth

Otodus megalodon

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

Limonite Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Coal (Bituminous Coal (organic sedimentary rock)) — sedimentary

Coal

Bituminous Coal (organic sedimentary rock)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Coal (Bituminous) (Organic sedimentary rock primarily consisting of carbon (C)) — sedimentary

Coal (Bituminous)

Organic sedimentary rock primarily consisting of carbon (C)

Citrine (Tumbled Quartz) (Silicon Dioxide (SiO2)) — mineral

Citrine (Tumbled Quartz)

Silicon Dioxide (SiO2)

Bituminous Coal (Organic-rich sedimentary rock (Complex hydrocarbons)) — sedimentary

Bituminous Coal

Organic-rich sedimentary rock (Complex hydrocarbons)

Diamond (Diamond (carbon allotrope), C (chemical formula)) — Mineral

Diamond

Diamond (carbon allotrope), C (chemical formula)

Ironstone / limonite-rich concretion (Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O), possibly with hematite) — mineral

Ironstone / limonite-rich concretion

Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O), possibly with hematite

Garnet (Almandine (Fe3Al2(SiO4)3)) — mineral

Garnet

Almandine (Fe3Al2(SiO4)3)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Serpentinite (Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4) — metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Barite (Desert Diamond) (Barite (Barium Sulfate, BaSO4)) — mineral

Barite (Desert Diamond)

Barite (Barium Sulfate, BaSO4)

Coquina (Fossiliferous Limestone) (Coquina (Organic Clastic Limestone)) — sedimentary

Coquina (Fossiliferous Limestone)

Coquina (Organic Clastic Limestone)

Calcite (Calcite (CaCO3)) — mineral

Calcite

Calcite (CaCO3)

Glaucophane Schist (Blueschist) (Glaucophane Schist) — metamorphic

Glaucophane Schist (Blueschist)

Glaucophane Schist

Rounded gray river cobble (Likely basalt or fine-grained mafic volcanic rock; exact identification requires testing) — igneous

Rounded gray river cobble

Likely basalt or fine-grained mafic volcanic rock; exact identification requires testing

Scoria (Vesicular Basalt / Scoria) — igneous

Scoria

Vesicular Basalt / Scoria

Tumbled yellow quartz (likely citrine or iron-stained quartz) (Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration) — mineral

Tumbled yellow quartz (likely citrine or iron-stained quartz)

Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration

Fluorite (Calcium fluoride (CaF2)) — mineral

Fluorite

Calcium fluoride (CaF2)

Green Fluorite (Fluorite (Calcium Fluoride, CaF2)) — mineral

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Black Agate (Chalcedony (SiO2)) — mineral

Black Agate

Chalcedony (SiO2)

Epidote (Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))) — metamorphic

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Green fluorite (likely polished/cut specimen) (Fluorite, calcium fluoride (CaF₂)) — mineral

Green fluorite (likely polished/cut specimen)

Fluorite, calcium fluoride (CaF₂)

Ferromanganese Nodule (Polymetallic Nodule (composed primarily of MnO2 and Fe2O3)) — sedimentary

Ferromanganese Nodule

Polymetallic Nodule (composed primarily of MnO2 and Fe2O3)

Green aventurine (likely) (Quartzite dominated by quartz (SiO₂), colored green by fuchsite mica or chlorite) — mineral

Green aventurine (likely)

Quartzite dominated by quartz (SiO₂), colored green by fuchsite mica or chlorite

Blue Schist / Lydian Stone / Chert with Glaucophane (Metamorphic rock containing quartz and glaucophane) — metamorphic

Blue Schist / Lydian Stone / Chert with Glaucophane

Metamorphic rock containing quartz and glaucophane

Green Fluorite (Fluorite (Calcium Fluoride, CaF2)) — mineral

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Ironstone Concretion (Limonite/Goethite) (Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)

Geode (unopened) (Quartz-filled Geode (SiO2)) — sedimentary

Geode (unopened)

Quartz-filled Geode (SiO2)

Tumbled purple fluorite (probable) (Fluorite, calcium fluoride (CaF₂)) — mineral

Tumbled purple fluorite (probable)

Fluorite, calcium fluoride (CaF₂)

Green Fluorite (Fluorite (Calcium Fluoride, CaF2)) — mineral

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Weathered iron-rich rock, possibly limonite/goethite (Limonite (hydrated iron oxides; commonly goethite, FeO(OH), mixed with hematite)) — mineral

Weathered iron-rich rock, possibly limonite/goethite

Limonite (hydrated iron oxides; commonly goethite, FeO(OH), mixed with hematite)

Barite (Barium Sulfate (BaSO4)) — mineral

Barite

Barium Sulfate (BaSO4)