Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
Category
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
Black Onyx
Black Chalcedony (SiO2)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
Olivine Diabase Porphyry
Porphyritic Olivine-Bearing Diabase (Micro-Gabbro)
Schist (Biotite/Mica Schist)
Medium-grade regional metamorphic rock (rich in Phyllosilicates)
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Sea Glass
Amorphous Silica (Anthropogenic glass) - SiO2
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Peridotite (Olivine)
Peridotite (comprising (Mg,Fe)2SiO4)
Artisanal Glass Beads (Simulated Goldstone or Aventurine Glass)
Silicon Dioxide (SiO2) with metallic inclusions
Chert (often called Flint)
Chert (Microcrystalline Quartz, SiO2)
Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
Ironstone Concretion
Limonitic/Hematitic Concretion
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Jasper with Iron Staining
Silicon Dioxide (SiO2) with impurities
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Quartzite
Quartzite (SiO2)
Ferruginous Quartzite (also known as Ironstone or Gossan)
Ferruginous Quartzite with Goethite/Hematite staining
Slag (Industrial Glassy Byproduct)
Anthropogenic silicate byproduct (Slag)
Gossan (Iron Hat) with Quartz and Chlorite
Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
Magnetite
Magnetite (Fe3O4)
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
Pyrite
Pyrite (FeS₂)
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
Serpentinite
Serpentinite (containing minerals of the Serpentine subgroup: Antigorite, Lizardite, and Chrysotile; formula (Mg,Fe)3Si2O5(OH)4)
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
Iron Slag
Anthropogenic Iron oxide/Silicate composite
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Synthetic Faux Fur Fursuit
Polyacrylonitrile / Polyester (Synthetic Textile)
Black Star Diopside
Diopside (CaMgSi2O6) with Magnetite inclusions
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
Asphalt Chunk (with aggregate)
Bituminous concrete / Anthropogenic conglomerate
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate