Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Sedimentary
Category
Mineral (Biogenic)
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Strawberry Quartz
Quartz (SiO2) with inclusions of Goethite or Hematite
Mineral
Azurite-Malachite (often a mixed specimen)
Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.
Mineral
Vesicular Basalt with Secondary Mineral Inclusions
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Pyrite
Iron Disulfide (FeS2)
mineral
Limonite (Iron Stone/Ocher)
Limonite (FeO(OH)·nH2O)
mineral
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Greenstone
Greenschist (containing chlorite, epidote, and actinolite)
metamorphic
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
sedimentary
Geode with Iron-Stained Quartz/Calcite
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix
sedimentary
Psilomelane (Black Hematite/Manganese Ore)
Barium Manganese Oxide (Formula: BaMn9O18(OH)4)
mineral
Red Sandstone
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)
sedimentary
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
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
Tiger's Eye
Tiger's Eye (SiO2 with crocidolite inclusions)
mineral
Amygdaloidal Rhyolite
Amygdaloidal felsic extrusive rock
igneous
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
metamorphic
Quartzite (River Cobble)
Quartzite (dominant mineral: Quatrz, SiO2)
metamorphic
Sandstone
Arenite (SiO2 based with mineral cement)
sedimentary
River Pebble (Brecciated Chert/Siltstone)
Silicon Dioxide (SiO2) with mineral inclusions
sedimentary
Black Jasper
Black Jasper (Silicate mineral - SiO2)
sedimentary
Goldstone
Not a natural mineral or rock. It is an ornamental glass.
Manufactured Glass (Simulant)
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock with secondary mineral fillings)
igneous
Sandstone (Quartz-rich)
Arenite (SiO2 based clastic rock)
sedimentary
Schist
Mica Schist
metamorphic
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Schist (with Iron Oxide)
Mica Schist
metamorphic
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
igneous
Epidote in Matrix (likely Amphibolite or Gneiss)
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix
metamorphic
Pegmatite (with smoky quartz and tourmaline/biotite)
Pegmatitic Granite
igneous
Man-made Slag (Industrial Byproduct)
Anthropogenic Glassy Residue
not a natural rock
Sandstone
Arenite (primarily SiO2)
sedimentary
Cinnabar
Mercury(II) sulfide (HgS)
mineral
Amygdaloidal Rhyolite (often called Lake Superior Agate relative)
Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)
igneous
Quartzite with inclusions
Metamorphic Rock (Mainly SiO2)
metamorphic
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
metamorphic
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Calamites (Fossil)
Calamites sp. (Tracheophyta, Equisetopsida)
sedimentary