Gneiss (Metamorphic Cobble)
Gneiss
metamorphic
Category
Metamorphic (Likely Gneiss Or Schist Based On Texture)
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
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Gneiss (with Quartzite and Biotite)
Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)
metamorphic
Weathered schist or gneiss cobble
Foliated silicate rock, likely mica schist or biotite gneiss
metamorphic
Quartz vein in weathered host rock
Milky quartz (SiO₂), likely in a granitic or metamorphic matrix
mineral
Banded gneiss pebble
Gneiss, typically quartz–feldspar–mica banded rock
metamorphic
Gneiss
Gneiss
metamorphic
Biotite (Mica)
Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Gneiss (possibly migmatitic or strongly folded banded gneiss)
Banded quartz–feldspar–mica gneiss; variable composition, commonly quartz + plagioclase/alkali feldspar + biotite/muscovite ± amphibole
metamorphic
Rounded metamorphic pebble, likely mica schist or gneiss
Mica schist/gneiss; commonly quartz, feldspar, and biotite or muscovite mica
metamorphic
Schist
Mica Schist
metamorphic
Gneiss
Gneiss
metamorphic
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Metamorphic, Mineral (within a rock type)
Gneiss
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Greenschist
Chlorite schist
metamorphic
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Greenschist
Chlorite Schist
metamorphic
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Mineral
Gneiss
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Quartz-veined metamorphic rock, likely schist or gneiss
Quartz–feldspar–mica rock; exact identification requires testing
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Garnet fragments
Garnet-group silicate, most likely almandine–pyrope or spessartine; composition varies, commonly (Fe,Mg,Mn)₃Al₂Si₃O₁₂
mineral
Gneiss
Gneiss
metamorphic
Quartz Vein in Matrix (Gneiss/Schist)
Silicon Dioxide (SiO2) in Metamorphic Rock Matrix
metamorphic
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
River Rock (Gneiss/Schist mix)
Foliated Metamorphic Rock (Gneiss)
metamorphic
Gneiss (Metamorphic Pebble)
Metamorphic Rock (Quartz-Feldspar-Biotite Gneiss)
metamorphic
Banded gneissic rock
Gneiss, likely quartz–feldspar–biotite gneiss
metamorphic
Gneiss
Foliated quartz–feldspar gneiss, likely biotite-bearing
metamorphic
Pink Garnet in Matrix
Grossular or Almandine Garnet (X3Y2(SiO4)3)
metamorphic
Likely raw mica-bearing metamorphic rock or mineral fragment
Tentatively biotite schist; visually similar dark mica-rich material
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Black Tourmaline
Schorl (NaFe3Al6(Si6O18)(BO3)3(OH,F)4)
mineral
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Weathered mafic metamorphic rock, likely amphibolite
Amphibolite; chiefly hornblende amphibole and plagioclase feldspar, with possible biotite, epidote, and quartz
metamorphic
Mica-rich schist, likely lepidolite or muscovite schist
Mica schist; predominantly muscovite KAl₂(AlSi₃O₁₀)(OH)₂, possibly lithium-rich lepidolite
metamorphic
Dark metamorphic rock, likely schist or slate fragment
Indeterminate; possibly biotite schist, chlorite schist, or slate
metamorphic