Rock Identifier

Category

Organic (Geological Relative)

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

Dark sulfide-bearing mineral specimen, possibly bornite or chalcopyrite (Likely chalcopyrite (CuFeS₂) or bornite (Cu₅FeS₄), with pale quartz or carbonate coating) — mineral

Dark sulfide-bearing mineral specimen, possibly bornite or chalcopyrite

Likely chalcopyrite (CuFeS₂) or bornite (Cu₅FeS₄), with pale quartz or carbonate coating

Green Calcite (Calcite (CaCO3)) — mineral

Green Calcite

Calcite (CaCO3)

Yellow Calcite (Calcium Carbonate (CaCO3)) — Mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

Basalt (Basalt (comprising plagioclase, pyroxene, and olivine)) — igneous

Basalt

Basalt (comprising plagioclase, pyroxene, and olivine)

Emerald (Beryl (Be3Al2(SiO3)6)) — gemstone

Emerald

Beryl (Be3Al2(SiO3)6)

Pink Granite (Granite (Felsic Plutonic Rock)) — igneous

Pink Granite

Granite (Felsic Plutonic Rock)

Green Calcite (often commercially called Green Onyx) (Calcium Carbonate (CaCO3)) — Mineral

Green Calcite (often commercially called Green Onyx)

Calcium Carbonate (CaCO3)

Red Coral (Precious Coral) (Corallium rubrum (Calcium Carbonate, CaCO3)) — sedimentary

Red Coral (Precious Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Malachite (possibly chrysocolla-bearing) (Malachite, Cu₂CO₃(OH)₂; the blue-green areas may include chrysocolla, Cu₂H₂Si₂O₅(OH)₄) — mineral

Malachite (possibly chrysocolla-bearing)

Malachite, Cu₂CO₃(OH)₂; the blue-green areas may include chrysocolla, Cu₂H₂Si₂O₅(OH)₄

Dark volcanic rock, likely basalt (Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, possibly with olivine) — igneous

Dark volcanic rock, likely basalt

Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, possibly with olivine

Weathered iron-rich rock, possibly limonite/goethite-bearing material (Limonite (hydrated iron oxides; commonly mixtures of goethite, hematite, and lepidocrocite)) — mineral

Weathered iron-rich rock, possibly limonite/goethite-bearing material

Limonite (hydrated iron oxides; commonly mixtures of goethite, hematite, and lepidocrocite)

Goethite–limonite ironstone (Goethite (α-FeO(OH)) with limonite, hydrated iron oxides, and possible quartz) — mineral

Goethite–limonite ironstone

Goethite (α-FeO(OH)) with limonite, hydrated iron oxides, and possible quartz

Honey calcite (likely rough calcite crystal) (Calcite, calcium carbonate (CaCO₃)) — mineral

Honey calcite (likely rough calcite crystal)

Calcite, calcium carbonate (CaCO₃)

Pale green glassy mineral fragment, possibly prehnite or fluorite (Probable prehnite (Ca₂Al₂Si₃O₁₀(OH)₂) or pale-green fluorite (CaF₂); exact identification requires testing) — mineral

Pale green glassy mineral fragment, possibly prehnite or fluorite

Probable prehnite (Ca₂Al₂Si₃O₁₀(OH)₂) or pale-green fluorite (CaF₂); exact identification requires testing

Turquoise beads (Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O) — gemstone

Turquoise beads

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Polished turquoise (Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O) — mineral

Polished turquoise

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Green copper-bearing mineral specimen, possibly chrysocolla or malachite (Tentatively chrysocolla, hydrated copper aluminosilicate; may include malachite, Cu₂CO₃(OH)₂) — mineral

Green copper-bearing mineral specimen, possibly chrysocolla or malachite

Tentatively chrysocolla, hydrated copper aluminosilicate; may include malachite, Cu₂CO₃(OH)₂

Basalt (Basalt (Aphanitic Mafic Volcanic Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Coarse-Grained Marble (Recrystallized Limestone (Major component: CaCO3)) — metamorphic

Coarse-Grained Marble

Recrystallized Limestone (Major component: CaCO3)

Ironstone / limonitic iron-rich rock (Goethite–hematite–limonite aggregate, commonly an ironstone concretion) — sedimentary

Ironstone / limonitic iron-rich rock

Goethite–hematite–limonite aggregate, commonly an ironstone concretion

Basalt (Vesicular and Scoria) (Basalt (extrusive volcanic rock)) — igneous

Basalt (Vesicular and Scoria)

Basalt (extrusive volcanic rock)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt (Basalt (extrusive volcanic rock)) — igneous

Basalt

Basalt (extrusive volcanic rock)

Pearls (likely freshwater cultured pearls) (Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin) — gemstone

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Pegmatite (Granitic Pegmatite) — igneous

Pegmatite

Granitic Pegmatite

Chert (Chert (SiO2)) — sedimentary

Chert

Chert (SiO2)

Limestone (or Calcite Pebble) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (or Calcite Pebble)

Calcium Carbonate (CaCO3)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline Quartz (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Mother of Pearl and Onyx (Aragonite (Mother of Pearl) and Chalcedony (Onyx)) — mineral

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Lava Rock (Scoria) (Scoria (Mafic volcanic rock)) — igneous

Lava Rock (Scoria)

Scoria (Mafic volcanic rock)

Tumbled green stone, likely malachite or aventurine (Malachite (Cu₂CO₃(OH)₂) or quartz-rich green aventurine (SiO₂ with fuchsite inclusions)) — mineral

Tumbled green stone, likely malachite or aventurine

Malachite (Cu₂CO₃(OH)₂) or quartz-rich green aventurine (SiO₂ with fuchsite inclusions)

Malachite specimen (Malachite, Cu₂CO₃(OH)₂, commonly intergrown with chrysocolla and minor copper oxides) — mineral

Malachite specimen

Malachite, Cu₂CO₃(OH)₂, commonly intergrown with chrysocolla and minor copper oxides

Tumbled pink calcite (Calcite (calcium carbonate, CaCO₃)) — mineral

Tumbled pink calcite

Calcite (calcium carbonate, CaCO₃)

Malachite-stained copper-bearing rock (Malachite, Cu₂CO₃(OH)₂, likely coating or alteration of copper sulfide/host rock) — mineral

Malachite-stained copper-bearing rock

Malachite, Cu₂CO₃(OH)₂, likely coating or alteration of copper sulfide/host rock

Turquoise cabochon ring (Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O) — gemstone

Turquoise cabochon ring

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Dyed or treated turquoise-like tumbled stone (Likely turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O), though blue-green magnesite or howlite imitation is possible) — mineral

Dyed or treated turquoise-like tumbled stone

Likely turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O), though blue-green magnesite or howlite imitation is possible

Blue-green fluorite crystal (Fluorite (calcium fluoride, CaF₂)) — mineral

Blue-green fluorite crystal

Fluorite (calcium fluoride, CaF₂)

Blue-green turquoise-like tumbled stone (Turquoise, hydrous copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O) — mineral

Blue-green turquoise-like tumbled stone

Turquoise, hydrous copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock