Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Category
Metamorphic Or Sedimentary Depending On Local Grade
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
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Chert Arrowhead (Lithic Artifact)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Gneiss
High-grade Metamorphic Gneiss
metamorphic
Slate
Foliated Metamorphic Rock (composed primarily of silica and alumina with iron and magnesium)
metamorphic
Fossiliferous Limestone with Fossil Fragment
Fossiliferous Limestone (CaCO3 with organic remains)
fossil
Banded gneiss
Gneiss, commonly quartz–feldspar–biotite gneiss
metamorphic
Garnet in Schist (Polished Tower)
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Dragon Blood Jasper
Epidote-containing Quartz and Chlorite (SiO2 + (Ca2(Al, Fe)3(SiO4)3(OH)))
sedimentary
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Weathered gray-green metamorphic pebble
Probable greenschist or chlorite-rich metavolcanic rock; exact identification requires testing
metamorphic
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Banded Gneiss
Metamorphic Gneiss
metamorphic
Orange Quartz with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate hydroxide (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
mineral
Garnet
Garnet group: X3Y2(SiO4)3 (commonly Almandine-Pyrope series)
mineral
Gneiss (Granitic Gneiss)
Gneiss
metamorphic
Fossilized bivalve or brachiopod fragment
Indeterminate fossil shell, likely calcitic or aragonitic carbonate
fossil
Iceland Spar (Optical Calcite)
Calcite (CaCO3)
mineral
Ruby in Zoisite
Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende
Metamorphic Rock (composed of multiple minerals)
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Crushed Limestone and Calcite
Calcium Carbonate (CaCO3)
sedimentary
Gneiss
Metamorphic Gneiss
metamorphic
Fossilized Bored Limestone
Limestone with Ichnofossils (Gastrochaenolites or Entobia)
sedimentary
Anthracite Coal
Anthracite (Carbon rank grade)
sedimentary
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
High-grade Metamorphic Gneiss
metamorphic
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Gneiss
Foliated Metamorphic Rock
metamorphic
Gneiss
Gneiss
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz Cluster
Crystalline Silicon Dioxide (SiO2)
mineral
Aquamarine
Beryl (Be3Al2(SiO3)6)
gemstone
Rainbow Moonstone (White Labradorite)
White Labradorite (Feldspar variety, (Na,Ca)(Al,Si)4O8)
mineral
Gneiss
High-grade Metamorphic Gneiss
metamorphic
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Slate
Foliated Metamorphic Rock
metamorphic
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz-rich metamorphic rock, likely quartzite
Quartzite; predominantly microcrystalline quartz (SiO₂), with minor dark mica or amphibole and possible feldspar
metamorphic
Biotite Schist
Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Engraved polished dark stone (likely slate or basalt)
Probable fine-grained slate (microcrystalline phyllosilicates), possibly basalt; exact identification requires testing
metamorphic
Feldspar (Potassium Feldspar / Orthoclase)
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Anthracite Coal
Anthracite coal (High-rank coal)
sedimentary