Gneiss (Metamorphic Cobble)
Gneiss
metamorphic
Category
Metamorphic Or Igneous (Context Dependent)
Browse metamorphic or igneous (context dependent) specimens identified by the Rock Identifier community.
Learn about Metamorphic Or Igneous (Context Dependent) in the encyclopedia
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Ruby (Corundum)
Aluminum Oxide (Al₂O₃:Cr)
gemstone
Small rounded quartz pebble
Quartz (SiO₂), likely milky or iron-stained quartz
mineral
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Banded Gneiss
Metamorphic Gneiss (High-grade regional metamorphism specimen)
metamorphic
Green Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2
mineral
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2
mineral
Schist
Mica Schist
metamorphic
Quartz-rich metamorphic rock (likely mica schist or gneiss)
Quartz–feldspar–mica assemblage; probable biotite schist/gneiss
metamorphic
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Greenstone (Greenschist)
Greenschist facies rock (containing chlorite, epidote, actinolite)
metamorphic
Beryl (var. Aquamarine/Blue Beryl) in Quartz Matrix
Beryllium Aluminum Silicate (Be3Al2Si6O18)
mineral
Schist
Mica Schist
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)
Biotite (Black Mica) in Host Rock
K(Mg,Fe)3AlSi3O10(OH,F)2
mineral
Milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Banded Gneiss with Quartz Vein
Foliated Metamorphic Rock (Gneiss)
metamorphic
Muscovite Mica
Muscovite KAl2(AlSi3O10)(OH)2
mineral
Graphite
Graphite (Chemical Formula: C)
Mineral (Native Element)
Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Yellow Aventurine
Quartz (SiO2) with inclusions
mineral
Greenstone with Pyrite inclusions
Greenschist / Meta-volcanic rock with Iron Disulfide (FeS2)
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Greenstone
Epidiorite / Altered Basalt
metamorphic
Gneiss
Gneiss
metamorphic
Gold Ore in Matrix
Native Gold (Au) in Quartz/Limonite host rock
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Greenstone / River Jadeite pebble
Metavolcanic rock / Chlorite or Actinolite-rich schist
metamorphic
Banded gneiss (likely amphibolite-rich gneiss)
Banded gneiss; composition commonly quartz, feldspar, mica and/or amphibole
metamorphic
Dragon Stone (Dragon Blood Jasper)
Epidote with Pietersite or Red Jasper inclusions (varied SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))
metamorphic
Tumbled or naturally etched mica-rich mineral specimen, likely muscovite
Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂; possibly phlogopite mica
mineral
Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon dioxide (SiO2)
mineral
White Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Red Jasper / Carnelian Chalcedony
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
gemstone
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Sand / Sandstone grains
Silicon Dioxide (SiO2)
sedimentary
Amazonite
Microcline Feldspar (KAlSi3O8)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral