Rock Identifier

Category

Organic (Geological Relative)

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

Tumbled basalt (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase, pyroxene, and commonly olivine) — igneous

Tumbled basalt

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase, pyroxene, and commonly olivine

Chrysocolla-rich copper ore (Chrysocolla (hydrated copper aluminosilicate), likely with malachite and copper oxides) — mineral

Chrysocolla-rich copper ore

Chrysocolla (hydrated copper aluminosilicate), likely with malachite and copper oxides

Tumbled dark pebble, likely basalt (Basalt, predominantly plagioclase feldspar and pyroxene, commonly with olivine or magnetite) — igneous

Tumbled dark pebble, likely basalt

Basalt, predominantly plagioclase feldspar and pyroxene, commonly with olivine or magnetite

Probable rough basalt or mafic igneous fragment (Fine-grained basalt, likely plagioclase–pyroxene–olivine aggregate) — igneous

Probable rough basalt or mafic igneous fragment

Fine-grained basalt, likely plagioclase–pyroxene–olivine aggregate

Likely basalt or other dark igneous rock (Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine) — igneous

Likely basalt or other dark igneous rock

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine

Siderite Concretion in Shale (Iron carbonate (FeCO3) in Mudstone/Shale matrix) — sedimentary

Siderite Concretion in Shale

Iron carbonate (FeCO3) in Mudstone/Shale matrix

Green Aventurine (Aventurine (a variety of Quartz, SiO2)) — Mineral

Green Aventurine

Aventurine (a variety of Quartz, SiO2)

Moss Agate (Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)

Fossilized Horn Coral (Order Rugosa (Rugose Coral)) — sedimentary

Fossilized Horn Coral

Order Rugosa (Rugose Coral)

Pink Opal / Peruvian Opal (Hydrated amorphous silicon dioxide (SiO2·nH2O)) — Mineral

Pink Opal / Peruvian Opal

Hydrated amorphous silicon dioxide (SiO2·nH2O)

Chrysocolla-bearing copper ore (Chrysocolla (hydrated copper aluminosilicate), commonly with malachite and quartz/matrix) — mineral

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminosilicate), commonly with malachite and quartz/matrix

Polished basalt pebble (Basalt, primarily plagioclase feldspar, pyroxene, and iron-titanium oxides) — igneous

Polished basalt pebble

Basalt, primarily plagioclase feldspar, pyroxene, and iron-titanium oxides

Possible basalt pebble (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene) — igneous

Possible basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene

Pumice (Pumice (volcanic glass formed of highly vesicular rough textured rock)) — igneous

Pumice

Pumice (volcanic glass formed of highly vesicular rough textured rock)

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

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chert / Jasper (Cryptocrystalline Silica (SiO2)) — sedimentary

Chert / Jasper

Cryptocrystalline Silica (SiO2)

Chert (Flint) (Microcrystalline Quartz or Cryptocrystalline Silica (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz or Cryptocrystalline Silica (SiO2)

Chert (Flint) (Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Silicon Dioxide (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Weathered ironstone concretion (probable limonite/goethite nodule) (Limonite-goethite-rich iron-oxide concretion; chiefly FeO(OH)·nH₂O) — mineral

Weathered ironstone concretion (probable limonite/goethite nodule)

Limonite-goethite-rich iron-oxide concretion; chiefly FeO(OH)·nH₂O

Concretion (Septarian Concretion (Fragmentary)) — sedimentary

Concretion

Septarian Concretion (Fragmentary)

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

Chert (Flint variety)

Silicon Dioxide (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Chert (Light Variety) (Sedimentary cryptocrystalline quartz (SiO2)) — sedimentary

Chert (Light Variety)

Sedimentary cryptocrystalline quartz (SiO2)

Fossiliferous Limestone (Calcite (CaCO3) with Bioclastic inclusions) — sedimentary

Fossiliferous Limestone

Calcite (CaCO3) with Bioclastic inclusions

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

Chert / Flint

Chert (Cryptocrystalline Quartz, SiO2)

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

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Black Jasper (Silicon Dioxide (SiO2) with impurities) — sedimentary

Black Jasper

Silicon Dioxide (SiO2) with impurities

Serpentinized ultramafic rock (probable serpentinite) (Serpentinite, dominated by serpentine-group minerals (lizardite/chrysotile/antigorite), with possible magnetite and carbonate) — metamorphic

Serpentinized ultramafic rock (probable serpentinite)

Serpentinite, dominated by serpentine-group minerals (lizardite/chrysotile/antigorite), with possible magnetite and carbonate

Sea Shell (Mollusk Shell) (Calcium Carbonate (Aragonite/Calcite)) — fossil

Sea Shell (Mollusk Shell)

Calcium Carbonate (Aragonite/Calcite)

Greenstone (Metamorphosed Mafic Igneous Rock) — metamorphic

Greenstone

Metamorphosed Mafic Igneous Rock

Unknown Organic Object (likely a berry or fruit) (Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.) — Organic Material (likely a fruit or berry)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Organic Material (likely a fruit or berry)

Weathered mafic rock, likely basalt (Basalt; fine-grained plagioclase–pyroxene rock, commonly with olivine and iron oxides) — igneous

Weathered mafic rock, likely basalt

Basalt; fine-grained plagioclase–pyroxene rock, commonly with olivine and iron oxides

Blue-green copper mineral specimen, likely chrysocolla (Chrysocolla, hydrated copper phyllosilicate — approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with turquoise or malachite) — mineral

Blue-green copper mineral specimen, likely chrysocolla

Chrysocolla, hydrated copper phyllosilicate — approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with turquoise or malachite

Fossil Coral (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Seashell (Cone Snail Shell) (Conus sp. (Calcium Carbonate, CaCO3)) — fossil

Seashell (Cone Snail Shell)

Conus sp. (Calcium Carbonate, CaCO3)

Ammonite Fossil (Polished Half / Cleoniceras) (Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite) — Sedimentary

Ammonite Fossil (Polished Half / Cleoniceras)

Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite

Dalmatian jasper (Quartz-bearing alkali feldspar syenite/porphyritic igneous rock, commonly marketed as Dalmatian jasper) — igneous

Dalmatian jasper

Quartz-bearing alkali feldspar syenite/porphyritic igneous rock, commonly marketed as Dalmatian jasper

Tumbled dark igneous rock, likely basalt (Basalt; commonly composed of plagioclase feldspar, pyroxene, and olivine) — igneous

Tumbled dark igneous rock, likely basalt

Basalt; commonly composed of plagioclase feldspar, pyroxene, and olivine

Seashell Fossil (Gastropoda fossil) — fossil

Seashell Fossil

Gastropoda fossil

Siltstone with Fossil Cast (Sedimentary Rock (Siltstone / Fine-grained Sandstone)) — sedimentary

Siltstone with Fossil Cast

Sedimentary Rock (Siltstone / Fine-grained Sandstone)