Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Chert / Chalcedony (likely carnelian or flint variety)
Silicon Dioxide (SiO2)
sedimentary
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
sedimentary
Garnet Gneiss
Garnetiferous Gneiss
metamorphic
Greywacke (likely)
Greywacke (a type of sandstone)
Sedimentary
Weathered granite or granitic gneiss
Felsic granitoid; primarily quartz, feldspar, and mica
igneous
Granite
Felsic intrusive igneous rock
igneous
Not a geological specimen
N/A (man-made object)
N/A
Quartz with inclusions (likely Chlorite or Hornblende) and country rock
SiO2 (Quartz) with associated ferromagnesian minerals
Mineral/Igneous/Metamorphic association
Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
sedimentary
Asphalt (Bituminous Slate/Sandstone)
Asphaltum / Bituminous Rock
sedimentary
Quartz Pebble (Geode Fragment / Druzy Cavity)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Hag Stone
Perforated sedimentary rock (typically flint, chert, or limestone)
sedimentary
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Sandstone or Quartzite pebble
Sandstone (Quartz arenite) or Quartzite
sedimentary or metamorphic
River Cobble (Basalt or Sandstone)
Weathered Basalt or Fine-Grained Sandstone
igneous
Mixed River Pebbles (including Unakite and Jasper)
Polymineralic geological specimens
igneous and sedimentary
Sandstone (Ferruginous)
Arenite (Siliclastic Sedimentary Rock)
sedimentary
Ferruginous Sandstone (Ironstone)
Arenite with Limonite/Goethite cement
sedimentary
Rounded gray pebble, likely quartz-rich stone
Indeterminate; possibly quartzite or a weathered granitic pebble
rock
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
mineral
Quartz Veined Rock (Likely Graywacke or Quartzite)
Silicon Dioxide (SiO2) veins in Metasedimentary matrix
metamorphic
Horn Coral Fossil
Rugosa (Tetracoralla)
fossil
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety
Mineral
Quartz geode or quartz-bearing rock
Quartz (SiO₂), likely in a chalcedony- or basalt-hosted cavity
mineral
Quartz-veined metamorphic rock, likely greenschist or altered metavolcanic
Chlorite–actinolite–epidote-bearing metavolcanic rock with quartz veins; exact identification requires testing
metamorphic
Weathered iron-rich rock, possibly limonite/goethite-bearing breccia
Hydrated iron oxides/hydroxides, mainly limonite (mixture) and goethite, FeO(OH)·nH₂O
mineral
Weathered iron-rich rock, possibly laterite or limonite-bearing quartzite
Limonite/goethite mixture, commonly FeO(OH)·nH₂O, with possible quartz and iron oxides
mineral
Quartz Vein in Matrix (Breccia / Host Rock with Quartz)
Silicon Dioxide (SiO2) in Host Rock Matrix
metamorphic
Granite
Intrusive Igneous Rock
igneous
Garnet Schist
Almandine Garnet-bearing Mica Schist
metamorphic
Quartz (Milky/Crystalline)
Silicon Dioxide (SiO2)
mineral
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
mineral
Quartzite (probable)
Quartzite; predominantly recrystallized quartz (SiO₂)
metamorphic
Limonite (after Pyrite Pseudomorph)
Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)
mineral
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
River Rock
N/A - Generic term for water-smoothed rock
sedimentary
River Stone (Sandstone with Oxide Banding)
Arenite with Iron/Manganese Oxide inclusions
sedimentary
Quartz (Milky Quartz vein fragment)
Silicon Dioxide (SiO2)
mineral