Limestone
Calcium Carbonate (CaCO3)
sedimentary
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Basalt
Extrusive Igneous Rock
igneous
Basalt Pebble
Extrusive Igneous Rock / Basalt
igneous
Serpentine
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3(Si, Al, Fe)2O5(OH)4
metamorphic
Granodiorite (Gneissic texture)
Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)
igneous
Basalt (Vesicular)
Basalt (Extrusive Volcanic Rock)
igneous
Granite, likely weathered biotite granite
Phaneritic intrusive igneous rock composed chiefly of quartz, feldspar, and biotite amphibole
igneous
Weathered volcanic rock, likely andesite or basaltic-andesite
Fine-grained plagioclase–pyroxene volcanic rock; possible altered andesite (exact identification requires testing)
igneous
Granite or granitic gneiss
Quartz–feldspar–mica granitoid; possibly foliated gneiss
igneous
Weathered granite or granitic gneiss
Quartz–feldspar–mica granitoid; possibly weakly gneissic
igneous
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within metamorphic/igneous matrix
igneous/metamorphic
Geode (Quartz / Chalcedony Geode)
SiO2 (Silicon Dioxide)
sedimentary
Weathered greenish rock fragment
Tentatively altered basalt or serpentinite; exact identification requires testing
igneous
Granite or Granitic Gneiss River Rock
Granite
igneous
Granite
Intrusive Igneous Rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Granite
Intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase
igneous
Granite
Intrusive Igneous Rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Limestone
Calcium carbonate (CaCO3)
sedimentary
Quartzite
Metamorphic Quartz Arenite
metamorphic
Quartz (or Chert/Flint)
Silicon Dioxide (SiO2)
mineral
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Granite
Granite (Intrusive Igneous Rock)
igneous
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Granite
Felsic intrusive igneous rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Flint / Chert (or fossiliferous nodule)
Microcrystalline quartz (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Granite or Porphyritic Igneous Rock (weathered)
Granitoid
Igneous
Small pale stone, likely quartzite or limestone fragment
Indeterminate; possible quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)
metamorphic or sedimentary
Gravel or Crushed Stone
Fragmented Aggregate Stone
sedimentary or igneous fragment
Rock Specimen
Unclassified rock specimen
sedimentary
Sandstone (with Rock Art)
Sandstone (Clastic Sedimentary Rock)
sedimentary
Rounded gray-brown pebble
Indeterminate; likely weathered quartz-rich sandstone or fine-grained volcanic rock
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral