Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) with iron and other impurities
Banded Chert (River Siltstone)
Microcrystalline Quartz (SiO2)
Wishing Stone (Sandstone with Quartz Vein)
Arenite with Quartzite intrusion (SiO₂)
Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Red Sandstone
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
River Rock (Basalt/Greywacke)
Aphanitic Basalt or Lithic Sandstone (Greywacke)
Quartz Druze (on Matrix)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Carnelian (Chalcedony)
Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities
Sandstone (Red Sandstone / River Stone)
Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)
Desert Rose
Gypsum (CaSO4·2H2O) or Baryte (BaSO4) with trapped sand grains
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Carnelian Agate
Silicon Dioxide (SiO2) with Iron Oxide impurities
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically a fragment with Desert Varnish)
Microcrystalline quartz (SiO2)
Coquina
Bioclastic Limestone
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with included minerals (Fuchsite for green)
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
Gneiss (with Quartz and Biotite Mica)
Gneiss
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Dyed Agate (Tumbled)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Basanite variety) with Quartz Vein
Microcrystalline Quartz (SiO2)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Red Jasper (with Quartz Veins)
Jasper (var. chert, SiO₂)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)