Psilomelane (Black Hematite/Manganese Ore)
Barium Manganese Oxide (Formula: BaMn9O18(OH)4)
mineral
Category
Mineral (Native Element Alloy)
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Red Sandstone
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)
sedimentary
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Zebra Jasper
Silicon Dioxide (SiO2) with various inclusions
metamorphic/sedimentary
Tiger's Eye
Tiger's Eye (SiO2 with crocidolite inclusions)
mineral
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
mineral
Tumbled Stones (various)
Mixed Silica-based Minerals (primarily Quartz and Chalcedony)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with inclusions of Dumortierite or similar minerals
mineral
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Borosilicate mineral/Quartz inclusion)
mineral
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
metamorphic
Quartzite (River Cobble)
Quartzite (dominant mineral: Quatrz, SiO2)
metamorphic
Sandstone
Arenite (SiO2 based with mineral cement)
sedimentary
Goldstone
Not a natural mineral or rock. It is an ornamental glass.
Manufactured Glass (Simulant)
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
metamorphic
Sunstone (Orthoclase Feldspar variant)
Orthoclase (KAlSi3O8) with inclusions
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Amygdaloidal Rhyolite
Amygdaloidal felsic extrusive rock
igneous
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock with secondary mineral fillings)
igneous
Schist
Mica Schist
metamorphic
Picture Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2 based clastic rock)
sedimentary
Epidote in Matrix (likely Amphibolite or Gneiss)
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix
metamorphic
Greenschist (containing Epidote and Quartz)
Greenschist (Epidote-Chlorite-Actinolite Schist)
metamorphic
Man-made Slag (Industrial Byproduct)
Anthropogenic Glassy Residue
not a natural rock
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
igneous
Schist (with Iron Oxide)
Mica Schist
metamorphic
Dyed Magnesite (often sold as Red Turquoise or Howlite)
Magnesium Carbonate (MgCO3)
mineral
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
metamorphic
Amygdaloidal Rhyolite (often called Lake Superior Agate relative)
Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Dyed Chalcedony (Agate)
Silicon Dioxide (SiO2) with artificial pigment
mineral
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Slate
Foliated Metamorphic Rock (composed primarily of silica and alumina with iron and magnesium)
metamorphic
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Sandstone
Arenite
sedimentary
Calamites (Fossil)
Calamites sp. (Tracheophyta, Equisetopsida)
sedimentary
Lapis Lazuli
Lapis lazuli (a rock primarily composed of Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Note regarding image quality
Indeterminate
Quartzite with inclusions
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
sedimentary (matrix) / mineral (inclusion)
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary