Limestone
CaCO3 (Mainly Calcite or Aragonite)
sedimentary
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.
Basalt
Mafic volcanic rock (Primarily Plagioclase Feldspar and Pyroxene)
Igneous
Sandstone (likely Greywacke or Lithic Sandstone)
Arenite / Wacke
sedimentary
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Mineral-like byproduct
Banded Gneiss (Variety of Gneiss)
Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)
Metamorphic Rock
Chalcedony (specifically Agate or Flint)
Silicon Dioxide (SiO₂)
Mineral
Scoria (Red Lava Rock)
Scoria
igneous
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Basalt (with possible mineral veining)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt Pebble
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Vesicular Basalt
Extrusive mafic igneous rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Andesite
Intermediate Volcanic Rock (Andesite)
igneous
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
sedimentary
Basalt
Basalt
igneous
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
igneous
Grey Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Andesite
Andesite (Intermediate Volcanic Rock)
igneous
Basalt
Basalt
igneous
Sandstone (with Limonite staining)
Arenite (FeOx-rich)
sedimentary
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
mineral
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
not a rock (anthropogenic material/technofossil)
Granite (specifically Brown Granite Countertop)
Phaneritic Felsic Igneous Rock (Granite-Gabbro series)
igneous
Pumice
Pumicite (Amorphous volcanic glass)
Igneous
Porphyritic Basalt
Porphyritic Basalt (containing Plagioclase or Alkali Feldspar phenocrysts)
igneous
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
igneous
Pumice
Pumice (volcanic glass froth)
igneous
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Sandstone with Quartz Vein
Arenite with SiO2 intrusion
sedimentary
Basalt
Extrusive mafic igneous rock
igneous
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (SiO2)
sedimentary
Porphyritic Basalt
Porphyritic Mafic Extrusive Rock
igneous
Basalt
Extrusive mafic igneous rock
igneous
Basalt
Extrusive mafic igneous rock
igneous
Basalt (River Pebble)
Basalt
igneous
Basalt with Iron Oxidation
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Basalt (Vesicular)
Extrusive Mafic Igneous Rock
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Banded Agate (specifically Sardonyx or Carnelian Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Sedimentary Rock (specifically a clastic sedimentary rock formed into a cobble)