Turquoise (small irregular fragment)
Turquoise, hydrated copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Greenstone pebble (possibly altered basalt)
Chlorite- and/or epidote-altered basalt; exact identification requires testing
igneous
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Likely weathered granite or granitic gneiss
Granite: quartz, feldspar, and mica; exact identification is uncertain from the image
igneous
Basalt (Vesicular Basalt / Scoria)
Vesicular Basalt
igneous
Milky Quartz Pebble with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Granite Pebble
Granite (Plutonic Igneous Rock)
igneous
Granite Pebble (Pegmatitic Quartz-Feldspar River Rock)
Granite / Quartz-Feldspar-Mica Aggregate
igneous
Sandstone with Desert Varnish
Arenite (SiO2 predominantly) with Ferromanganese coating
sedimentary
Rounded brown pebble (rock type undetermined)
Unidentified, iron-stained lithic pebble; composition cannot be determined from the photograph
sedimentary
Gossan (with Limonite/Hematite coating)
Ferruginous Gossan (Fe2O3·nH2O / Fe2O3)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Red Granite
Granite
igneous
Basalt
Mafic extrusive igneous rock
igneous
Rhyolite
Extrusive felsic igneous rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Red Sandstone
Sedimentary rock primarily composed of quartz sand grains
sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Sedimentary Rock (Limestone or Siltstone pebble)
Sedimentary rock fragment
sedimentary
Slate
Metamorphic Pelitic Rock
metamorphic
Weathered iron-rich rock, possibly limonite-bearing basalt or laterite
Indeterminate; likely Fe-oxide/hydroxide–altered mafic rock, dominated by limonite/goethite with silicate minerals
igneous
Limestone bedrock
Limestone, chiefly calcite (CaCO₃)
sedimentary
Smooth gray pebbles
Unidentified rounded rock fragments; composition cannot be determined from the image
igneous
Red Sandstone
Sedimentary Litharenite / Quartz Arenite
sedimentary
Green Slate
Metamorphic Pelite
metamorphic
Granite
Felsic intrusive igneous rock
igneous
Granite
Intrusive Igneous Rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Iron-stained weathered rock
Unknown
Unknown (likely sedimentary or metamorphic)
Granite Pebble
Intrusive Igneous Rock
igneous
Likely bituminous coal
Coal, predominantly carbon-rich organic matter; rank and composition cannot be confirmed from the image
sedimentary
Weathered geode or vug-bearing rock
Likely a quartz- or calcite-lined geode/vug in a host rock; exact minerals cannot be confirmed from the image
mineral
Red Sandstone
Arenite (primarily quartz with iron oxide cement)
sedimentary
Pale greenish quartz-bearing rock, possibly serpentine or altered feldspar
Tentatively serpentinite-related rock (serpentine-group minerals) or altered granitic material; identification is uncertain from the photograph
metamorphic
Small rounded pebble
Unidentified lithic pebble; composition cannot be determined from the image
sedimentary
Granite Pebble
Granite (Plutonic Igneous Rock)
igneous
Quartzite Pebble (Stream-rounded Quartz/Quartzite Gravel)
Quartzite / Silicon Dioxide (SiO2)
metamorphic
Rough garnet-bearing rock, likely almandine garnet in matrix
Almandine garnet, Fe₃Al₂(SiO₄)₃; exact host rock cannot be determined from the image
metamorphic
Copper Ore / Altered Granodiorite
Cupriferous rock with silicate gangue
mineral