Amethyst
Amethyst (SiO2 - Silicon Dioxide with iron impurities)
Category
Browse igneous or sedimentary (anthropogenic modification) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (SiO2 - Silicon Dioxide with iron impurities)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss (specifically a weathered or stream-worn specimen)
Gneiss (Foliated Metamorphic Rock)
Gneiss
Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)
Carnelian
Silicon dioxide (SiO2) with iron oxide impurities
Gneiss
Gneiss (High-grade Metamorphic Rock)
Gneiss
Gneiss
Gneiss
Metamorphic Gneiss
Gneiss with Quartz Vein
Gneiss (containing SiO2 vein)
Gneiss
Gneiss (High-grade regional metamorphic rock)
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
Sandstone-based Concrete Fragment
Cementitious Composite with Sedimentary Aggregate
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Magnetite / Ironstone
Magnetite (Fe3O4)
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Gneiss
Metamorphic Gneiss
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Apatite
Fluorapatite (Ca5(PO4)3F)
Dalmatian Jasper
Aplite with Arfvedsonite inclusions
Druzy Quartz (on Geode Fragment)
Silicon Dioxide (SiO2)
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
Magnetite
Iron(II,III) oxide (Fe3O4)
Bloodstone Jasper (Heliotrope)
SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
Brown Chalcedony (Agate/Jasper blend)
Silicon dioxide (SiO2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Quartz Heart or Arrowhead Shape
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Mica
Mica group (often Muscovite or Biotite)
Clear Quartz
SiO2 (Silicon Dioxide)
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Gneiss
Gneiss (High-grade metamorphic rock)
Quartz (Rose Quartz or Jasper variety)
Silicon Dioxide (SiO2)
Green Calcite
Calcium Carbonate (CaCO3)
Apatite
Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)
Apatite
Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)
Quartz
Silicon Dioxide (SiO2)