Limonite
FeO(OH)·nH2O (Hydrated iron oxide)
Category
Browse sedimentary (biogenic sediment or biological remain) specimens identified by the Rock Identifier community.
Limonite
FeO(OH)·nH2O (Hydrated iron oxide)
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Carnelian Agate
Chalcedony (SiO2) with iron oxide inclusions
Red Jasper
Jasper (Silicon Dioxide) - SiO2
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Calcite Geode
Calcium Carbonate (CaCO3)
Smoky Quartz (Apache Tear Variety)
Silicon dioxide (SiO2) - Volcanic Glass
Bauxite (Concretionary)
Bauxite (Al(OH)3, AlO(OH))
Transit Token (RTD Denver)
Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)
Limestone
Calcium carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Fossiliferous)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Mica Schist
Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)
Ferruginous Sandstone
Ferruginous Clastic Sedimentary Rock
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Chalcedony (Carnelian/Agate variety)
Silicon Dioxide (SiO2) with trace hematite/iron impurities
Rock Salt (Halite)
Halite (Sodium Chloride, NaCl)
Pyrite (Fools Gold)
Iron Sulfide (FeS2)
Yellow Quartzite or Yellow Jasper
Quartzite (primarily SiO2 with Iron oxide staining)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Limonite with Hematite
Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Carnelian
Carnelian (SiO2)
Nobby Hematite (Iron Ore)
Hematite (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Magnetite / Iron Ore
Magnetite (Fe3O4)
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
Zoisite with Ruby (Anyolite)
Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)
Carnelian
Carnelian (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Calcite
Calcium Carbonate (CaCO3)
Goethite (Iron Ore)
Goethite (FeO(OH))
Limestone
Calcium Carbonate (CaCO3)