Mineral Description (Anthropogenic Material)

Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.

Siltstone

Siltstone (fined-grained clastic sedimentary rock)

sedimentary

Quartzite

Quartzite (SiO2)

metamorphic

Quartzite with Iron Staining

Silicon Dioxide (SiO2) with Fe2O3 impurities

metamorphic

Gowganda Tillite (Puddingstone)

Glacial Tillite (Diamictite) with Jasper inclusions

sedimentary

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

sedimentary

Siltstone or Mudstone

Argillaceous sedimentary rock

sedimentary

Gowganda Tillite (Puddingstone)

Glacial Diamictite (Gowganda Formation)

sedimentary

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with iron oxide cement)

sedimentary

White Marble

Recrystallized Calcite (CaCO3)

metamorphic

Marble

Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)

metamorphic

Clear Quartz (Rock Crystal)

Quartz (SiO₂)

Mineral

Granite Pebble

Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica/amphibole)

igneous

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Mineral

Aventurine

Aventurine Quartz (SiO2 with inclusions)

Mineral

Chert (Flint variety)

Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2

sedimentary

Chert (Flint variety)

Chert (SiO2)

sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

sedimentary

Bauxite Ore

Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)

Mineral

Botryoidal Chalcedony with Calcite

Chalcedony (SiO2 with accessory minerals, likely CaCO3)

Mineral

Sandstone

Arenite (general term for sandstone)

Sedimentary Rock

Man-made Crystal (Lead Glass)

Lead oxide-doped Silica Glass (approx. SiO2 + PbO)

Mineraloid/Synthetic Material

Quartz (likely)

Quartz (SiO2 - Silicon Dioxide)

Mineral

Basalt

Basalt (a mafic extrusive igneous rock)

Igneous

Quartz

Quartz (SiO2)

Mineral

Garnet (likely Pyrope or Almandine)

Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.

Mineral