Sandstone
Arenite (SiO2 predominantly)
Category
Browse antropogenic rock (man made) specimens identified by the Rock Identifier community.
Sandstone
Arenite (SiO2 predominantly)
Basalt
Extrusive Mafic Igneous Rock
Basalt River Cobble
Basalt (Composition primarily Plagioclase Feldspar and Pyroxene)
Basalt (River Cobble)
Basalt (Mafic Extrusive Igneous Rock)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Serpentinite
Serpentinite (a rock composed predominantly of serpentine group minerals)
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Quartz in Host Rock
Silicon Dioxide (SiO2) in Rhyolite or Granite matrix
Basalt
Basalt
Thunderegg (Ate Agate/Jasper Geode)
Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)
Basalt
Mafic Igneous Rock
Gold in Quartz Matrix
Native Gold (Au) with Quartz (SiO2) and Slate/Shale
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
Gneiss
High-grade Metamorphic Gneiss
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Basalt
Mafic Igneous Rock
Basalt (River Stone)
Mafic volcanic rock
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Granite
Granitoid
Granodiorite (River Rock / Cobble)
Granodiorite; Phaneritic intrusive igneous rock dominated by plagioclase, quartz, and hornblende/biotite
Unakite
Epidotized Granite (Composed of Orthoclase Feldspar, Epidote, and Quartz)
Quartz-veined Siltstone
Siltstone with Quartz (SiO2) veins
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
Andesite Porphyry
Andesite (extrusive volcanic rock)
Vesicular Basalt
Mafic Igneous Rock
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
Basalt
Basalt (Mafic volcanic rock)
Agate Geode Slice (with Druzy Quartz)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Gneiss
Gneiss (a type of metamorphic rock)
Sandstone or Siltstone
Arenite (if sandstone)
Druzy Quartz on Limestone
Silicon Dioxide (SiO2)
Granite (Specimen: Logan Rock)
Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)
Sandstone (likely Arkosic)
Arenite (SiO2 with KAlSi3O8)
Limestone (Weathered)
Calcium Carbonate (CaCO3)
Chert (Quartzite-rich River Pebble)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement