Clear Quartz Sphere
Silicon Dioxide (SiO2)
Category
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Clear Quartz Sphere
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Agate (River Pea)
Microcrystalline Chalcedony (SiO2)
Granite
Phaneritic Felsic Intrusive Igneous Rock
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 with inclusions)
Sandstone (Yellow/Tan)
Clastic sedimentary rock (primarily SiO2 with iron oxide staining)
Massive Quartz
Silicon Dioxide (SiO2)
Quartz with Mica inclusions (likely Schist or Gneiss host)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)
Quartz Pebble
Silicon Dioxide (SiO2)
Uncertain small pale mineral fragment
Indeterminate; possibly calcite or a light-colored feldspar fragment
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Rough Quartz (with potential Host Rock)
Silicon Dioxide (SiO2)
Chert (Chalky Flint Node)
Chert (Microcrystalline Quartz, SiO2)
Chert (often called Flint or River Stone)
Microcrystalline alpha-quartz (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Phantom Quartz with Chlorite and Hematite inclusions
Silicon Dioxide (SiO2) with inclusions of Chlorite group minerals and Hematite (Fe2O3)
Quartz druzy geode
Quartz, silicon dioxide (SiO₂), microcrystalline/druzy variety
Fossiliferous Limestone (Hash)
Bioclastic Grainstone / Calcarenite
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Sandstone
Arenite (SiO2 principal component)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Greenish-gray quartz-rich rock, possibly weathered granite or quartzite
Provisional identification: quartz–feldspar aggregate; exact species cannot be confirmed from one photograph
Quartz (Raw Specimen)
Silicon Dioxide (SiO2)
Granite
Granite (Phaneritic Quartz-Feldspar rock)
Fossilized bivalve shell in limestone
Calcitic fossil shell; likely an oyster or other rudist/bivalve (Bivalvia), preserved in carbonate rock
Optical Calcite
Calcite (Calcium Carbonate, CaCO3)
Chert (and Agate/Chalcedony)
Microcrystalline Quartz (SiO2)
Quartz-bearing rock fragment
Likely quartz (SiO₂) with iron-oxide staining and possible host-rock grains
Weathered iron-rich rock, possibly limonite-bearing sandstone
Limonite/goethite mixture, approximately hydrated iron oxides (FeO(OH)·nH₂O), possibly coating sandstone or ironstone
Serpentinized ultramafic rock (likely serpentinite)
Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, olivine, pyroxene, and sulfides
Grey River Stone (Quartz-rich Quartzite/Siltstone)
Quartzite / Meta-siltstone (primarily SiO2)
Quartz
Silicon dioxide (SiO2)
Quartzite
Metamorphic Quartz Sandstone
Chert (Flint nodule)
Chert (SiO2)
Jasper / Chert (Red)
Cryptocrystalline quartz (SiO2)
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 based)