Fuchsite (Green Muscovite)
K(Al,Cr)2(AlSi3O10)(OH)2
Category
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
Fuchsite (Green Muscovite)
K(Al,Cr)2(AlSi3O10)(OH)2
Green Schist
Greenschist (containing Chlorite, Actinolite, and Epidote)
Black Tourmaline (Schorl)
Schorl (NaFe2+3Al6(BO3)3Si6O18(OH)4)
Banded gneiss
Gneiss; chiefly quartz, feldspar, and mica
Sandstone
Sandstone (SiO2 dominant)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Lapis Lazuli (in jewelry setting)
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite-rich rock)
Blue opalite (often sold as synthetic opal)
Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Quartz vein rock with iron-stained matrix
Quartz (SiO₂), likely with limonite/goethite and minor feldspar or mica
Quartz with Mica (Gneissic or Pegmatitic origin)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(F,OH)2)
Sapphire
Corundum (Al₂O₃) with trace elements causing color variations.
Potassium Feldspar
K-Feldspar (KAlSi3O8)
Granitoid (Granite/Granodiorite)
Plutonic igneous rock (variable composition, primarily SiO2)
Greenstone
Chlorite schist or Epidosite
Riverstone Quartzite / Chalcedony Nugget
Silicon Dioxide (SiO2)
Rhyolitic Tuff
Rhyolitic Tuff / Pyroclastic rock
Beryl (Emerald variety in host rock)
Be3Al2(SiO3)6 (Silicate mineral)
Tumbled brown quartzite or jasper
Quartzite (mostly SiO₂), possibly iron-rich jasper (microcrystalline quartz)
Greenish Metamorphic Rock (likely containing epidote or chlorite)
Metamorphic rock, possibly epidosite or greenstone
Granite
Intrusive Phaneritic Felsic Igneous Rock
Green Aventurine
Quartz (Silicon Dioxide) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Green Aventurine
Tectosilicate, variety of Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Graphite-bearing quartz-mica schist
Graphite-rich quartz–mica schist; primarily quartz (SiO₂), muscovite/biotite, and graphite (C)
Granite
Intrusive Phaneritic Felsic Igneous Rock
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Black Tourmaline (Schorl)
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Ruby (Raw Corundum)
Corundum (Al2O3 with Chromium impurities)
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Red Sandstone
Arenite
Citrine
Citrine (Silicon Dioxide - SiO2)
Greenstone (Metabalt)
Chlorite schist / Epidiorite
Quartz geode or druzy quartz specimen
Quartz, silicon dioxide (SiO₂), likely microcrystalline/drusy quartz coating a host rock
Orthoclase Feldspar
KAlSi3O8 (Potassium aluminum silicate)
Orthoclase Feldspar
Potassium Feldspar (KAlSi3O8)
Yellow Sapphire
Corundum (Al2O3) with iron impurities
Kyanite
Kyanite (Al2SiO5)
Banded Gneiss
Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica)
Iolite-bearing Gneiss (Cordierite)
Cordierite (Mg2Al4Si5O18) in Gneiss matrix
Schist (Garnet-Mica Schist)
Garnet-Mica Schist
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)