Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
Category
Browse igneous or sedimentary specimens identified by the Rock Identifier community.
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
Quartz Pebble
Silicon Dioxide (SiO2)
Yellow Quartz Pebble (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Yellow Agate
Chalcedony (cryptocrystalline Quartz), SiO2
Blue Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss
Granite Gneiss
High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)
Agate Geode
Cryptocrystalline Quartz (SiO2)
Pyrite (Iron Pyrite)
Iron Sulfide (FeS2)
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Carnelian
Carnelian Agate (Silica: SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Gneiss (Granitic Gneiss)
Gneiss (from German Gneis, related to 'spark')
Fluorite
Calcium Fluoride (CaF2)
Milky Quartz
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Pyrite
Iron Disulfide (FeS2)
Fluorite (Rainbow Fluorite Point)
Calcium Fluoride (CaF2)
Hematite
Iron(III) oxide (Fe2O3)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
Quartz
SiO₂ (Silicon Dioxide)
Red Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
Labradorite (tumbled)
Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Quartz (Milky/Smoky variety on matrix)
Silicon Dioxide (SiO2)
Quartz River Pebbles
Silicon Dioxide (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2)
Gneiss (Stream-worn Cobble)
Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)
Green Schist
Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)
Quartz (Milky/Cloudy Variety)
Silicon Dioxide (SiO2)
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
Chalcedony (Agate/Chert)
Silicon Dioxide (SiO₂)
Carnelian
Carnelian (Microcrystalline Quartz, SiO2)
Pyrite
Iron Disulfide (FeS2)
Yellow Quartz (Citrine Quartz or Yellow Chalcedony)
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Gneiss
Gneiss (High-grade metamorphic rock)
Arkosic Sandstone
Arkose
Biotite (Mica)
Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)