Gneiss
Gneiss (High-grade metamorphic rock)
Category
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade metamorphic rock)
Quartzite
Quartzite (composed primarily of SiO2)
Quartzite Cobble
Quartzite (composed primarily of SiO2)
Quartzite
Quartzite (composed primarily of SiO2)
Unakite
Unakite (Altered Granite composed of Orthoclase KAlSi3O8, Epidote Ca2(Al, Fe)3(SiO4)3(OH), and Quartz SiO2)
Greenschist with Quartz Veining
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
Schist with Quartz/Mica
Mica Schist (primarily Muscovite and Quartz)
Iron-stained Quartzite / Chert
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Granite (Weathered/Oxidized)
Phaneritic Felsic Igneous Rock (composed of Quartz, Orthoclase Feldspar, and Mica)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Granite
Phaneritic intrusive felsic igneous rock
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Quartz Mica Schist
Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)
Clear Quartz
Silicon Dioxide (SiO2)
Dyed Dalmatian Jasper (Dalmatian Stone)
Perthitic Feldspar with Arfvedsonite inclusions
Red Quartzite River Stone
Metamorphic Rock (composed mainly of Quartz, SiO2)
Mica Schist
Crystalline Schist (often containing Muscovite, Biotite, and Quartz)
Dalmatian Stone
Dalmatian Jasper (Aplitic Perthite)
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (composed primarily of Fluorapatite)
Gneiss Pebble
Gneiss
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Granite
Granite (a plutonic igneous rock composed primarily of quartz and feldspar)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Greenschist
Greenschist facies rock
Schist (Garnet-Mica Schist)
Garnet-Mica Schist (X-Y)3Z2(SiO4)3
Sandstone (with Lichen)
Arenite (primarily SiO2)
Gneiss (with Quartzite and Mica)
Gneiss
Nuummite
Nuummite (Orthorhombic amphiboles: Anthophyllite and Gedrite)
Schist
Schist (metamorphic rock)
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
Greenstone
Greenschist (composed of actinolite, chlorite, and epidote)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Schist (Micaceous Schist)
Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Schist
Mica Schist
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
Granite
Granite (Phaneritic intrusion / SiO2 + KAlSi3O8 + NaAlSi3O8)
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))