Basalt
Extrusive mafic igneous rock
Category
Browse rock specimens identified by the Rock Identifier community.
Basalt
Extrusive mafic igneous rock
Puddingstone (Conglomerate)
Conglomerate (clastic sedimentary rock)
Granite
Granite (Phaneritic igneous rock)
Conglomerate
Conglomerate (clastic sedimentary rock)
Basalt (River Stone)
Aphanitic Mafic Igneous Rock
Granite
Granite (Phaneritic Igneous Rock)
Marble
Recrystallized Carbonate Rock (CaCO3)
Granite
Phaneritic Felsic Igneous Rock
Pumice
Pumice (Vitreous volcanic rock)
Granite
Phaneritic plutonic rock (Felsic)
Basalt
Extrusive mafic igneous rock
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Dark Igneous Rock (Likely Basalt or Diabase)
Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Ocean Jasper
Spherulitic Chalcedony (SiO2)
Quartzite
Quartzite (primarily SiO2)
Serpentine
Serpentinite (complex of Mg, Fe, Ni, Al, Zn, Mn)Si2O5(OH)4
Quartz (Milky Quartz/Citrine Type)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Carnelian Agate
Silicon Dioxide (SiO2)
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Banded River Rock / Gneiss (highly weathered)
Gneiss
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Granite (River Pebble)
Phaneritic intrusive igneous rock (Felsic)
Kimberlite
Kimberlite (Potassic ultramafic volcanic rock)
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
Unidentifiable Specimen
Undetermined
Granitoid (Granitic Rock)
Granitoid (Quartzo-feldspathic plutonic rock)
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Garnetiferous Quartzite (Garnet Gneiss Pebble)
Garnet-bearing Quartzite or Quartz-Feldspar Gneiss
Basalt
Basalt (Aphanitic mafic volcanic rock)
Diorite
Diorite (Intermediate intrusive igneous rock)
Sandstone (likely Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Granite
Phaneritic Felsic Igneous Rock (Granite)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt (Water-worn pebble)
Basalt (Aphanitic mafic volcanic rock)
Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Extrusive mafic igneous rock
Sandstone
Clastic sedimentary rock (primarily SiO2)
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff