Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Red Sandstone
Clastic sedimentary rock (primarily Quartz and Feldspar with Iron Oxide cement)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Sandstone with Iron Concretion
Arenite with Limonite/Goethite Concretion
Turquoise (set in silver jewelry)
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Fossiliferous Limestone with Brachiopod Mold
Calcium Carbonate (CaCO3) matrix containing Brachiopoda fossil impressions
Jasper (Iron-stained Quartz)
Silicon Dioxide (SiO2) with iron oxide inclusions
Limestone (specifically Fossiliferous or Crinoidal Limestone)
Calcium Carbonate (CaCO3) - Calcite Rock
Fossil Coral
Coral Limestone (a type of biogenic sedimentary rock)
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Stromatolite
Biogenic Sedimentary Rock (Lithified microbial mat)
Chert (variations include Flint or Jasper)
Chert (chemical sedimentary rock), Quartz (SiO2)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
Anthracite Coal
Anthracite (Carbon-rich metamorphic sedimentary rock)
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Ironstone (Limonitic Shale)
Ferruginous Siltstone / Goethite-rich Sedimentary Rock
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Chert (often called Flint or Jasper depending on color)
Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Gneiss
Gneiss (high-grade metamorphic rock)
Gneiss
Gneiss (Metamorphic rock)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Coal
Bituminous or Anthracite coal (carbon-rich sedimentary rock)
Granitic Sand
Detrital sediment (predominantly Quartz, Feldspar, and Mica)
Tree Agate
Silicon Dioxide (SiO2) with Chlorite inclusions
Chert (and Flint)
Cryptocrystalline Quartz (SiO2)
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
Sandstone
Arenite
Clear Quartz (Druzy)
Crystalline Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 predominantly)
Hag Stone
Perforated Chert (Microcrystalline Silica, SiO2)
Chert (specifically Flint)
Microcrystalline quartz (SiO2)
Chert (Nodular Chert)
Silicon Dioxide (SiO2)