Gneiss
Gneiss (foliated metamorphic rock)
Category
Browse mineral (impactite) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (foliated metamorphic rock)
Granite with Mafic Xenolith
Intrusive Igneous Rock (Felsic to Intermediate)
Amygdaloidal Basalt with Quartz Veining
Basalt (Extrusive Igneous Rock) with Quartz (SiO2) veining
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Granite
Granite (Felsic Plutonic Rock)
Fossil Shark Tooth
Carcharocles (Otodus) sp. or similar fossilized Chondrichthyes tooth
Banded Sandstone (Water-worn Pebble)
Arenite with mineral banding
Limonite pseudo-concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
Limonite Stained Basalt
Hydrated Iron Oxide on Mafic Volcanic Rock (FeO(OH)·nH2O)
Pyrite with Quartz
Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)
Granite
Intrusive Igneous Rock
Quartz-rich pegmatite fragment
Granite-family pegmatite; chiefly quartz (SiO₂), feldspar, and black mica (biotite)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Banded Sedimentary Rock
Stratified Siliciclastic / Arenite or Siltstone with Mineral Bands
Fossil Sea Urchin (Echinoid)
Echinoidea fossil (often replaced by silica or calcite)
Granite
Felsic intrusive igneous rock
Nephrite Jade
Nephrite
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
Mica Schist / Granite
Mica Schist (Silicate metamorphic rock)
Quartz on Schist
Silicon Dioxide (SiO2) on Foliated Metamorphic Rock
Granite
Intrusive igneous felsic rock
Polished copper-bearing mineral specimen, likely malachite-rich copper ore
Malachite, Cu₂CO₃(OH)₂, possibly mixed with chrysocolla or limonite
Gravel and Pebbles
Unconsolidated rock fragments / detrital sediment
Fossilized Shark Tooth
Chondrichthyes (Class)
Fossil Shark Tooth
Carcharodon or Carcharias fossil (Vertebrate Fossil)
Kidney Stone (Urolith / Calcium Oxalate Stone)
Calcium Oxalate Monohydrate (Whewellite) / Calcium Oxalate Dihydrate (Weddellite)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz-rich pegmatite (likely feldspar–quartz rock)
Granitic pegmatite; chiefly quartz (SiO₂) and feldspar, with possible mica/iron-oxide staining
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Fluorite Tower
Fluorite (Calcium Fluoride - CaF2)
Granite (likely weathered granite or granitic gneiss)
Granite; chiefly quartz (SiO₂), feldspar, and mica
Spinosaurus fossil (permineralized bone)
Spinosaurus aegyptiacus (Calcium phosphate mineralized with silica/sediment)
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Gneiss
Gneiss
Botryoidal Hematite
Iron(III) oxide (Fe2O3)
Vanadinite
Lead Chlorovanadate, Pb5(VO4)3Cl
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O