Basalt
Basalt
Category
Browse industrial byproduct (anthropogenic rock like material) specimens identified by the Rock Identifier community.
Basalt
Basalt
Larimar
Pectolite [NaCa2Si3O8(OH)] with copper substitution
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
Sandstone (with possibly iron oxides and other minerals)
Sandstone
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)
Epidote with Feldspar/Quartz (Unakite-like)
Epidotized Granite (Ca2(Al,Fe)3(SiO4)3(OH) + KAlSi3O8)
Chert (variations include Flint or Jasper)
Chert (chemical sedimentary rock), Quartz (SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Ruby, Emerald, and Sapphire (Corundum and Beryl)
Corundum (Al2O3) and Beryl (Be3Al2Si6O18)
Diamond
Natural Diamond (Carbon, C)
Goldstone
Avventurina (Cu + SiO2 glass)
Ironstone Concretion / Goethite-Hematite Geode
Goethite / Hematite Concretion (Fe3O4 / FeO(OH) / Fe2O3)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Silver Nugget
Native Silver (Ag)
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Fossiliferous Limestone
Bioclastic Limestone (Calcium Carbonate, CaCO3)
Red Garnet (Pyrope or Almandine)
Garnet Group (A3B2(SiO4)3)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Chert Nodules or Concretion
Cryptocrystalline Quartz (SiO2)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Serpentine
Serpentine group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al)2O5(OH)4)
Crushed Granite / Landscaping Gravel
Granitoid
Biotite Mica
K(Mg,Fe)3AlSi3O10(OH)2
Weathered iron-rich rock, likely limonite/goethite-bearing laterite
Limonite–goethite aggregate, commonly approximated as hydrated iron oxides (FeO(OH)·nH₂O)
Milky Quartz
Quartz / Silicon Dioxide (SiO2)
Granite
Phaneritic Igneous Rock
Likely schist, possibly serpentinite
Mica schist; potential chlorite–serpentine-rich metamorphic rock
Agate
Silicon Dioxide (Chalcedony), SiO2
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Dyed Agate
Cryptocrystalline variety of Silica (SiO2)
Fossil Coral
Rugose Coral or Tabulate Coral (Phylum Cnidaria)
Tumbled White Quartz
Silicon Dioxide (SiO2)
Moss agate bracelet
Chalcedony (microcrystalline quartz, SiO₂) with chlorite/amphibole inclusions
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
River Stone (likely Quartzite or Limestone)
Silicon dioxide (SiO2) or Calcium carbonate (CaCO3)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Polished fluorite sphere
Fluorite (calcium fluoride, CaF₂)
Banded Calcite
Calcite (Calcium Carbonate, CaCO3)
Coquina or Fossilized Shell Aggregate
Calcareous bioclastic sedimentary rock (CaCO3)
Red Sandstone
Ferruginous Sandstone (SiO2 + Fe2O3)
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)