Gneiss
Gneiss
metamorphic
Category
Sedimentary Or Metamorphic (Base Substrate)
Browse sedimentary or metamorphic (base substrate) specimens identified by the Rock Identifier community.
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Mica Schist
Mica Schist (Silicate rock)
metamorphic
Likely biotite-rich schist
Mica schist, likely biotite-rich; exact minerals cannot be confirmed from the photo
metamorphic
Biotite Schist
Biotite Gneiss/Schist (approximate formula K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Gneiss with Quartz Veining
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Fuchsite in Quartz
K(Al,Cr)2(AlSi3O10)(OH)2 (Muscovite with Chromium)
metamorphic
Anthracite Coal
Anthracite (Carbon based fossil fuel)
metamorphic
Greenschist
Chlorite schist
metamorphic
Muscovite Mica (with Schist)
Muscovite - KAl2(AlSi3O10)(OH)2
metamorphic
Kaolinite (Kaolin)
Kaolinite (Al2Si2O5(OH)4)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Dark gray rounded river pebble
Likely basalt or fine-grained volcanic rock; exact identification requires testing
igneous
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
mineral
Amphibolite / Biotite Schist
Amphibolite (rich in Hornblende and Plagioclase feldspar)
metamorphic
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
metamorphic
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
metamorphic
Mica Schist with Garnet
Garnetiferous Mica Schist
metamorphic
Likely muscovite-bearing mica schist
Mica schist, composed chiefly of muscovite (KAl₂(AlSi₃O₁₀)(OH)₂) and quartz; exact identification is uncertain from the image alone.
metamorphic
Epidote-bearing Rock / Epidote Inclusion
Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) in host rock
mineral
Muscovite Mica Schist
Muscovite-rich schist
metamorphic
Gneiss (with Quartz-Feldspar vein)
Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)
metamorphic
Weathered dark stone, possibly basalt
Basalt; commonly plagioclase feldspar, pyroxene, and minor olivine
igneous
Biotite Schist
Biotite Mica Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Pumice
Felsic/intermediate vesicular extrusive rock
igneous
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Muscovite Mica Schist
Metamorphic Rock (Muscovite-Biotite Schist)
metamorphic
Gold-colored mineral specimen, likely pyrite or weathered mica schist
Tentatively pyrite (FeS₂); identification is uncertain from the obscured image
mineral
Likely mica-rich schist
Mica schist, composed mainly of muscovite and/or biotite with quartz; exact identification is uncertain from the photo.
metamorphic
Green Fuchsite and Quartz
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
metamorphic
Mica-rich Schist fragment
Mica Schist
metamorphic
K2 Stone
Azurite in Granite
igneous
Quartz-veined Gneiss
Gneiss with Quartz (SiO2) intrusions
metamorphic
Quartzite Pebble (River Rock)
Metamorphic Quartzite (predominantly SiO2)
metamorphic
Granitic Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Banded Quartzite
Quartzite (primarily SiO2)
metamorphic
River Cobble (Quartzite or Gneiss)
Metamorphic crystalline rock (predominantly SiO2 based)
metamorphic
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Epidote
Ca2(Al,Fe)3(SiO4)3(OH)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Graphite
Graphite (Carbon, C)
mineral
Slate
Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)
metamorphic