Gneiss
Gneiss
metamorphic
Category
Mineral (Extraterrestrial)
Browse mineral (extraterrestrial) specimens identified by the Rock Identifier community.
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Diorite (Salt and Pepper Rock)
Diorite
igneous
Gneiss
Gneiss
metamorphic
Concrete with Aggregate
Artificial Conglomerate (Cement and Aggregate)
sedimentary
Gneiss (Banded Gneiss)
Gneiss
metamorphic
Sandstone (likely Arkosic or Lithic)
Clastic Sedimentary Rock (SiO2 with accessory minerals)
sedimentary
Small pale mineral fragment
Unidentified; possibly quartz, calcite, or feldspar
mineral
Limonite Ironstone
Goethite-Limonite concretion / Iron oxide
sedimentary
Metamorphic rock with large feldspar crystals (likely porphyroblastic gneiss)
Feldspar-porphyroblastic gneiss; likely quartz and feldspar with mica/amphibole, identification from image only
metamorphic
Banded Gneiss
Gneiss (Foliated Metamorphic Rock)
metamorphic
Granite
Granite (composed mainly of Quartz, Potassium Feldspar, Plagioclase, and Biotite/Mica)
igneous
Gneiss (specifically Granite Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Pebble with vesicles, likely basalt
Vesicular basalt; chiefly plagioclase, pyroxene, and iron-magnesium minerals
igneous
Serpentinite
Serpentine-group minerals, chiefly antigorite, lizardite, and chrysotile; approximate formula Mg3Si2O5(OH)4
metamorphic
K-Feldspar (Potassium Feldspar)
Potassium Feldspar (KAlSi3O8)
mineral
Mica / Muscovite or Biotite
Phyllosilicate mineral group (e.g., KAl2(AlSi3O10)(OH)2)
mineral
Chalcopyrite (Peacock Ore)
Chalcopyrite (CuFeS2)
mineral
Botryoidal Chalcedony / Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Mica (Muscovite or Biotite)
Sheet silicate mineral group (e.g., KAl2(AlSi3O10)(F,OH)2)
mineral
Feldspar
Aluminosilicate (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8)
mineral
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
mineral
Tiger's Eye
Quartz pseudomorph after crocidolite (SiO2)
gemstone
Schist
Schist (various mineral compositions)
Metamorphic
Small weathered fossil or mineral fragment
Indeterminate; possibly fossilized shell, bone, or a pale carbonate mineral
fossil
Banded Sandstone (Beach Pebble)
Quartz Arenite Sandstone
sedimentary
Serpentine (likely serpentinite)
Serpentine-group minerals, chiefly antigorite, lizardite, and/or chrysotile; commonly with magnetite and minor brucite
metamorphic
Milky quartz (rough quartz crystal)
Quartz, silicon dioxide (SiO₂)
mineral
Unidentified metallic mineral or meteorite fragment
Indeterminate; possible native metal-bearing sulfide or iron meteorite fragment
mineral
Tumbled agate/chalcedony
Microcrystalline quartz (SiO₂), likely mossy or dendritic agate with iron-oxide inclusions
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Talc Schist / Soapstone
Talc (Mg3Si4O10(OH)2)
metamorphic
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Limonite with Pyrite
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH2O
mineral
Gneiss
Gneiss (a rock type, not a specific mineral with a formula)
Metamorphic Rock
Quartz with Sulfide Inclusions
Silicon Dioxide (SiO2) with metallic mineral inclusions
mineral
Fine-grained brown-gray rock, possibly andesite
Likely andesite or another fine-grained volcanic rock; exact identification is uncertain from the photo
igneous
Devil's Toenail (Fossil Oyster)
Gryphaea arcuata (Calcium Carbonate, CaCO3)
sedimentary
Weathered geode or vug-bearing rock
Likely a quartz- or calcite-lined geode/vug in a host rock; exact minerals cannot be confirmed from the image
mineral
Limonite or Goethite (Ironstone)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Kaolinite (China Clay)
Kaolinite (Al2Si2O5(OH)4)
sedimentary
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)
mineral