Pumice
Pumice (Amorphous volcanic glass)
Igneous
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Serpentinite
Antigorite, Lizardite, and Chrysotile (Mg3Si2O5(OH)4)
metamorphic
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
sedimentary
River Stone (likely Basalt or Greywacke)
Basalt with mineral veining
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Granite
Intrusive Igneous Rock
igneous
Quartz-veined weathered host rock
Quartz (SiO₂) in a likely altered limestone or metamorphic carbonate host
metamorphic
Weathered iron-rich rock, likely limonite/goethite-bearing laterite
Limonite–goethite aggregate, commonly approximated as hydrated iron oxides (FeO(OH)·nH₂O)
mineral
Quartz Geode
Crystalline Quartz (SiO2) within a sedimentary/igneous host
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a sedimentary or volcanic host
mineral
Geode (Unopened)
Siliceous Geode (SiO2)
sedimentary
Grey River Pebble (Greywacke / Basalt)
Stream-rounded silicate rock pebble
sedimentary
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite
Granite
igneous
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Basalt
Extrusive Igneous Rock
igneous
Agate Geode
Silicon Dioxide (SiO2)
mineral
Granite
Intrusive Igneous Rock
igneous
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
sedimentary
Polished petrified wood (agate/chalcedony replacement)
Silicified wood, chiefly microcrystalline quartz (SiO₂), often with iron-oxide coloration
fossil
Likely basalt (possibly fine-grained gabbro)
Basalt; predominantly plagioclase feldspar, pyroxene, and commonly olivine
igneous
Dark gray fine-grained stone, likely basalt
Basalt; mainly plagioclase feldspar, pyroxene, and sometimes olivine
igneous
Serpentine
Antigorite/Chrysotile group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al,Fe)2O5(OH)4)
metamorphic
Basalt
Afanitic Mafic Basalt
igneous
Basalt
Mafic volcanic rock (primarily plagioclase, pyroxene, and olivine)
Igneous
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Basalt with Quartz/Calcite Veins
Aphanitic Mafic Igneous Rock (Hydrothermal Veined)
igneous
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
igneous
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
sedimentary
Vesicular Basalt (Scoria)
Vesicular Basalt
igneous
Banded metamorphic rock, likely gneiss or metasedimentary slate
Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins
metamorphic
Dalmatian Jasper
Peralkaline Quartz-Feldspar Rock with Arfvedsonite
igneous
Dalmatian Stone
Dalmatian Jasper (Aplite rock composition)
igneous
Sandstone (Wonderstone)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Basalt
Extrusive igneous rock
igneous
Weathered iron-rich rock fragment
Likely limonite/goethite with hematite and iron-bearing silicates; exact identification requires testing
mineral
Rough turquoise-bearing rock (probable turquoise matrix)
Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a host-rock matrix
mineral
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
mineral
Granodiorite or Diorite
Granodiorite / Diorite
igneous
Weathered sandstone
Quartz-rich sandstone, locally iron-oxide stained (SiO₂-dominant)
sedimentary