Rock Identifier

Category

Rock

Browse rock specimens identified by the Rock Identifier community.

Learn about Rock in the encyclopedia

Rock Gypsum

Coral Rock

Rock Salt

Asphalt Rock

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Cataclasite

Anorthosite

Peridotite

Gondite

Phosphorite

Epidosite

Granite (Granite; primarily quartz, feldspar, and mica) — igneous

Granite

Granite; primarily quartz, feldspar, and mica

Serpentine (Serpentine subgroup (Mg,Fe)3Si2O5(OH)4) — metamorphic

Serpentine

Serpentine subgroup (Mg,Fe)3Si2O5(OH)4

Serpentine ((Mg,Fe)3Si2O5(OH)4) — metamorphic

Serpentine

(Mg,Fe)3Si2O5(OH)4

Generic Pebble (Lithic Fragment) — sedimentary

Generic Pebble

Lithic Fragment

Serpentinite (Serpentinite (composed primarily of Serpentine group minerals (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Granite (Granite) — igneous

Granite

Granite

Granite (Granite) — igneous

Granite

Granite

Possibly garnet-bearing rock fragment (Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.) — mineral

Possibly garnet-bearing rock fragment

Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.

Shale (Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)) — sedimentary

Shale

Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)

Vesicular Basalt (or Scoria) (Mafic extrusive igneous rock with vesicles) — igneous

Vesicular Basalt (or Scoria)

Mafic extrusive igneous rock with vesicles

Unidentified dark pebble (Unknown) — rock

Unidentified dark pebble

Unknown

Vesicular Basalt (Lava Rock) (Vesicular Basalt) — igneous

Vesicular Basalt (Lava Rock)

Vesicular Basalt

Weathered basalt or volcanic breccia (Fine-grained mafic volcanic rock, likely basalt (plagioclase–pyroxene ± olivine), possibly brecciated) — igneous

Weathered basalt or volcanic breccia

Fine-grained mafic volcanic rock, likely basalt (plagioclase–pyroxene ± olivine), possibly brecciated

Granite (likely biotite-bearing granite) (Granite, composed mainly of quartz, feldspar, and mica (likely biotite)) — igneous

Granite (likely biotite-bearing granite)

Granite, composed mainly of quartz, feldspar, and mica (likely biotite)

Weathered gneissic or granitic rock (Quartz–feldspar–biotite gneiss (tentative; possibly weathered granite)) — metamorphic

Weathered gneissic or granitic rock

Quartz–feldspar–biotite gneiss (tentative; possibly weathered granite)

Quartz Vein in Amphibolite / Gneiss (Quartz (SiO2) in Mafic Metamorphic Host Rock) — metamorphic

Quartz Vein in Amphibolite / Gneiss

Quartz (SiO2) in Mafic Metamorphic Host Rock

Small rounded pebble (Unidentified lithic pebble; composition cannot be determined from the image) — sedimentary

Small rounded pebble

Unidentified lithic pebble; composition cannot be determined from the image

River Pebble (Granite/Gneiss) (Granitic Pebble / Quartz-Feldspar Aggregate) — igneous

River Pebble (Granite/Gneiss)

Granitic Pebble / Quartz-Feldspar Aggregate

River Pebble (Siltstone / Fine-grained Sandstone) (Sedimentary Pebble (Siliclastic)) — sedimentary

River Pebble (Siltstone / Fine-grained Sandstone)

Sedimentary Pebble (Siliclastic)

Quartzite Pebble (Iron-stained Quartz) (Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — metamorphic

Quartzite Pebble (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Dark gray fine-grained rock fragment (Possibly andesite or basalt; exact identification is not possible from the image alone) — igneous

Dark gray fine-grained rock fragment

Possibly andesite or basalt; exact identification is not possible from the image alone

Weathered fine-grained rock, likely mudstone or siltstone (Indeterminate clastic sedimentary rock; likely lithified clay- and silt-sized grains) — sedimentary

Weathered fine-grained rock, likely mudstone or siltstone

Indeterminate clastic sedimentary rock; likely lithified clay- and silt-sized grains

Rounded quartz-veined pebble (Likely quartz-veined metamorphic rock; exact host rock is indeterminate from the image) — metamorphic

Rounded quartz-veined pebble

Likely quartz-veined metamorphic rock; exact host rock is indeterminate from the image

Likely greenstone (chlorite/epidote-altered basalt), waterworn pebble (Greenschist-facies metabasalt; commonly composed of chlorite, actinolite, epidote, and albite) — metamorphic

Likely greenstone (chlorite/epidote-altered basalt), waterworn pebble

Greenschist-facies metabasalt; commonly composed of chlorite, actinolite, epidote, and albite

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

Serpentine

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

K-Feldspar Granite Fragment (Felsic Plutonic Rock (Granite)) — igneous

K-Feldspar Granite Fragment

Felsic Plutonic Rock (Granite)

Garnet Schist (Garnetiferous Micaceous Schist) — metamorphic

Garnet Schist

Garnetiferous Micaceous Schist

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Granite (Felsic intrusive igneous rock) — igneous

Granite

Felsic intrusive igneous rock

Generic Rock Sample (Undetermined geological specimen) — igneous

Generic Rock Sample

Undetermined geological specimen

Vesicular Basalt (or Scoraceous Basalt) (Basalt (Vesicular texture)) — igneous

Vesicular Basalt (or Scoraceous Basalt)

Basalt (Vesicular texture)

Unidentified rock fragments (Indeterminate; likely a weathered, iron-stained silicate rock) — mineral

Unidentified rock fragments

Indeterminate; likely a weathered, iron-stained silicate rock

Sandstone (Arenite (SiO2 dominant)) — sedimentary

Sandstone

Arenite (SiO2 dominant)

Sandstone (Quartz Sandstone (predominantly)) — Sedimentary

Sandstone

Quartz Sandstone (predominantly)

Smoky Quartz and Chalcedony Geode Fragment (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Porphyritic Basalt (Porphyritic Basalt with Plagioclase Phenocrysts) — igneous

Porphyritic Basalt

Porphyritic Basalt with Plagioclase Phenocrysts

Geode (Quartz nodule / Chalcedony-lined cavity) — sedimentary

Geode

Quartz nodule / Chalcedony-lined cavity

Sandstone (Arenite (SiO2, often with CaCO3 or Fe2O3 cement)) — sedimentary

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

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

Serpentine

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

Serpentine (Antigorite, Lizardite, or Chrysotile (Mg3Si2O5(OH)4)) — metamorphic

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg3Si2O5(OH)4)

Basalt with Xenolith (Extrusive Igneous Rock containing Mantle Xenolith) — igneous

Basalt with Xenolith

Extrusive Igneous Rock containing Mantle Xenolith