Limestone
Calcium Carbonate (CaCO3)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz (Common or Milky)
Silicon Dioxide (SiO2)
Basalt
Extrusive mafic igneous rock
Basalt (River Pebble)
Basalt (Aphanitic Mafic Igneous Rock)
Shale
Laminated Mudstone
Quartz (Raw Chunk)
Silicon Dioxide (SiO2)
Scoria (Lava Rock)
Scoria (highly vesicular extrusive igneous rock)
Limonite stained Sandstone
Sedimentary rock with Goethite/Limonite (FeO(OH)·nH2O)
Quartz pebble (Quartztite fragment)
Silicon Dioxide (SiO2)
Magnetite
Magnetite (Fe3O4)
Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
Basalt
Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
Pumice
Vesicular volcanic glass
Asphalt (Aggregate)
Bituminous macadam / Concrete Aggregate
Sandstone with Quartz Veining
Clastic sedimentary rock (SiO2 dominated)
Agate (or Chalcedony)
SiO2 (Silicon Dioxide) - a cryptocrystalline variety of quartz
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Quartz Crystal
Quartz (SiO₂)
Basalt
Basalt (Mafic Extrusive)
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
Vesicular Basalt
Extrusive Mafic Igneous Rock (composed of Plagioclase feldspar, Pyroxene, and Olivine)
Diorite (River Pebble)
Diorite (Intermediate intrusive igneous rock)
Limonite (Ironstone)
Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone or Mudstone
Sedimentary Rock (Sandstone/Mudstone)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Sandstone (likely Calcareous or Micaceous)
Clastic sedimentary rock (primarily Quartz with Cementing Agents)
Red Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Pumice
Pumice (a highly vesicular extrusive igneous rock, primarily amorphous silica)
Basalt
Basalt (containing mainly Plagioclase feldspar and Pyroxene)
Granite
Granite (Phaneritic intrusive igneous rock)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Sandstone (likely Siltstone variety)
Arenite / Siltstone (primary mineral SiO2)
Basalt
Extrusive mafic igneous rock
Gabbro
Phaneritic Mafic Igneous Rock
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt (Mafic volcanic rock)