Optical Calcite (Iceland Spar)
Calcite (CaCO3)
Category
Browse sedimentary (jasper), mineral (aquamarine) specimens identified by the Rock Identifier community.
Optical Calcite (Iceland Spar)
Calcite (CaCO3)
Garnet (Almandine)
Almandine, Fe3Al2Si3O12
Specular Hematite with Quartz and Limonite
Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)
Native Gold (in earring form)
Gold (Au)
Calcite
Calcium Carbonate (CaCO3)
Pyrite with Iron Oxides (Fool's Gold in Matrix)
Iron Sulfide (FeS2)
Specular Hematite (Polished Sphere)
Hematite (Alpha Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)
Agate
Banded Chalcedony (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
Red Sandstone
Arenite (Ferruginous Sandstone)
Sandstone
Arenite (primarily Quartz, SiO2)
Sandstone (Quartzose)
Arenite (composed mainly of SiO2)
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
Sandstone
Clastic Sedimentary Rock (primarily SiO2)
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
Hematite Nodule
Hematite (Fe2O3)
Sandstone (with Liesegang rings or Oxidation)
Arenite (primarily Quartz SiO2 with Iron Oxide Fe2O3 staining)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz, SiO2)
Banded Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily Quartzite and Feldspar grains)
Sandstone (Quartz-rich)
Clastic sedimentary rock (SiO2 primary)
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
Sandstone Concretion
Sedimentary Concretion (SiO2 or CaCO3 cemented)
Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
Sandstone (likely Arkose)
Arenite (Feldspathic Sandstone / Arkose)
Turquoise
Hydrated phosphate of copper and aluminum - CuAl6(PO4)4(OH)8·4H2O
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Clear Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Gneiss (Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Amethyst (Raw Quartz)
Silicon Dioxide (SiO2) with iron impurities
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
Sandstone
Arenite (primarily SiO2)
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Bauxite
Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)
Herkimer Diamond (Quartz Crystal)
Silicon Dioxide (SiO2)
Limonite (Gozzany Iron)
Limonite (FeO(OH)·nH2O)