Banded Calcite (often sold as Onyx)
Calcite (Calcium Carbonate, CaCO3)
Category
Browse amorphous solid specimens identified by the Rock Identifier community.
Banded Calcite (often sold as Onyx)
Calcite (Calcium Carbonate, CaCO3)
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Gabbro
Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Chalk
Calcium Carbonate (CaCO3)
Crushed Limestone
Sedimentary Carbonate Rock (CaCO3)
Vesicular Basalt
Basalt with vesicular texture
Grey Quartzite Pebble
Quartzite (primarily SiO2)
Granite (Weathered River Rock)
Plutonic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Sandstone (River Cobble)
Arenite
River Pebble (Basalt/Greywacke)
Weathered Basalt or Fine-Grained Greywacke
Granite
Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)
Quartzite River Rock
Quartzite (primarily SiO2)
Greywacke (River Slikenside)
Greywacke (Lithic Sandstone)
Basalt (Purple-tinted scoria/vesicular variety)
Extrusive mafic igneous rock (SiO2 range 45–52%)
River Cobble (Basaltic/Andesitic)
Mafic Igneous Porphyritic Rock
Basalt with Quartz Veins
Vesicular or aphanitic Basalt with SiO2 (Quartz) intrusions
Riverstone (Water-worn Quartzite)
Quartzite (SiO2)
Basalt River Pebble
Aphanitic Mafic Basalt
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartzite
Quartzite
Pyrite
Iron Sulfide (FeS2)
Yellow Quartzite (River Stone)
Quartzite (primarily SiO2)
Granitic Gneiss
Gneiss (Metamorphic Rock)
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
Gabbro
Gabbro
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Gneiss
Gneiss (High-grade metamorphic rock)
Diorite (with Salt-and-Pepper Texture)
Diorite (Intrusive Igneous Rock)
Quartz Geode
Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell
Staurolite
Staurolite (Fe2+2Al9Si4O23(OH))
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and K-feldspar)
Banded Calcite (often sold as Caribbean Calcite or Mexican Onyx)
Calcium Carbonate (CaCO3)
Banded Calcite (often sold as Onyx Marble)
Calcite (Calcium Carbonate, CaCO3)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Banded Calcite (often sold as Yellow Aragonite or Onyx)
Calcium Carbonate (CaCO3)
Banded Calcite (often sold as Mexican Onyx or Aragonite)
Calcite/Aragonite (Calcium Carbonate, CaCO3)
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)