Opal
Hydrated Silica (SiO2·nH2O)
Category
Browse mineral and sedimentary specimens identified by the Rock Identifier community.
Opal
Hydrated Silica (SiO2·nH2O)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Bauxite
Bauxite (principal ore of aluminum, primarily Al(OH)3)
Bauxite (Laterite)
Hydrated aluminum oxides (Al2O3·nH2O)
Blue Chalcedony
Chalcedony (Silicon Dioxide, SiO2)
Blue Chalcedony
Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)
Sandstone
Arenite
Sandstone
Arenite
Sandstone (likely Conglomerate or Gritstone)
Arenite (SiO2 based)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
Chert (Jasper/Flint variety)
Sedimentary silica (SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Milky Quartz
Silicon Dioxide (SiO2)
Ironstone Concretion (Limonite/Goethite)
Ironstone (primarily FeO(OH)·nH2O)
Ironstone Concretion (Moqui Marble type)
Ferruginous Concretion (Fe2O3 / FeO(OH))
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
Quartz
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Litharenite)
Fluorite
Calcium Fluoride (CaF2)
Pyrite
Iron Disulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Green Calcite
Calcium Carbonate (CaCO3)
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Black Obsidian and Hematite
Volcanic Glass (SiO2) and Hematite (Fe2O3)
Gypsum Wallboard (Drywall)
Hydrous calcium sulfate (CaSO4·2H2O)
Pyrite and Chalcopyrite in Fluorite Matrix
Calcium Fluoride (CaF2) with Iron Sulfide (FeS2)
Kyanite
Kyanite (Al2SiO5)
Pyrulite (Pyrite / Chalcopyrite)
Iron Sulfide (FeS2) or Copper Iron Sulfide (CuFeS2)
Pyrite
Iron Sulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone
Arenite
Granitic Gneiss
Gneiss (Metamorphic rock predominantly containing quartz, K-feldspar, and plagioclase)
Blue Chalcedony
Chalcedony (SiO2)