Gneiss
High-grade regional metamorphic rock (Foliated)
metamorphic
Category
Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Sandstone (likely Arkosic)
Arenite (SiO2 with KAlSi3O8)
sedimentary
Basalt with Scoria/Vesicular texture
Vesicular Basalt (primarily Plagioclase feldspar, Pyroxene, and Olivine)
igneous
Basalt
Basalt (Mafic Extrusive)
igneous
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Pumice
Vesicular Rhyolite / Glassy Igneous Rock
igneous
Basalt
Basalt (Mainly Plagioclase Feldspar and Pyroxene)
igneous
Pyrite
Iron Pyrite (FeS2)
Mineral
Basalt
Basalt (containing Pyroxene, Plagioclase Feldspar, and Olivine)
igneous
Piddock-bored Mudstone
Lutite (Siltstone or Mudstone) with Pholad borings
sedimentary
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
mineral
Basalt with Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily Plagioclase Feldspar, Pyroxene, and Olivine)
igneous
Granite
Granite (a phaneritic intrusive igneous rock)
igneous
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
igneous
Concrete with Aggregate
Artificial Conglomerate (Cement and Aggregate)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
sedimentary
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
sedimentary
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Basalt (River Pebble)
Basalt (extrusive mafic rock)
igneous
Basalt
Extrusive Mafic Igneous Rock
igneous
Scoria (often called Lava Rock)
Vesicular Basalt / Scoria
igneous
Chert (variations include Flint or Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
sedimentary
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Pebble (likely Quartzite or Chert)
Clastic Sediment, potentially composed of SiO₂ (Quartz)
Mineral, Sediment
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Basalt
Mafic volcanic rock (consisting mostly of plagioclase, pyroxene, and olivine)
igneous
Pumice
Pumice (Vesicular volcanic glass)
igneous
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (Fossiliferous)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Quartz (Milky/Crystalline)
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Sedimentary
Coquina
Bioclastic Limestone (Coquina)
sedimentary
Unidentified Rock Fragment
Unknown
Rock
Sandstone
Arenite (SiO2 primarily)
sedimentary
Porphyritic Andesite
Andesite (Porphyry)
igneous
Basalt River Stone (Tumbled)
Basalt (Mafic Extrusive Igneous Rock)
igneous
Fossiliferous Sedimentary Rock (Coquina/Limestone)
Fossiliferous Calcarenite / Bioclastic Limestone
sedimentary
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Veined Limestone (Micrite) with Quartz/Calcite Veins
Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions
sedimentary