Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Category
Metamorphic (Likely Gneiss Or Schist Based On Texture)
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
Learn about Metamorphic (Likely Gneiss Or Schist Based On Texture) in the encyclopedia
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River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2)
metamorphic or sedimentary
Ruby
Corundum (Al2O3 with Chromium)
mineral
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium impurities)
mineral
Red Sandstone (Siltstone pebble)
Arenite / Siltstone (Silicon dioxide based with hematite impurities)
sedimentary
Quartzite Chert Pebble
Microcrystalline Silicon Dioxide (SiO2)
sedimentary/metamorphic
Quartz-rich gneiss
Banded quartz–feldspar–mica gneiss; commonly containing biotite and muscovite
metamorphic
Banded gneiss pebble
Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole
metamorphic
Greenschist
Chlorite schist (Metamorphic rock dominated by chlorite, epidote, and actinolite)
metamorphic
Sandstone concretion (Ironstone-stained)
Arenite with Limonite/Hematite staining (Silica-based with Iron Oxides)
sedimentary
Quartzite Pebble (River Rock)
Metamorphic Quartzite (predominantly SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
Sedimentary or Metamorphic
Black Tourmaline (Schorl)
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH
mineral
Granitic Gravel
Granite (Quartz, Feldspar, and Mica mixture)
igneous
Weathered quartz-rich metamorphic rock, likely quartzite
Quartzite; predominantly quartz (SiO₂), possibly with feldspar, mica, and iron-oxide staining
metamorphic
Garnet in Matrix (Schist or Quartz)
Almandine Garnet, Fe3Al2(SiO4)3
metamorphic
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
igneous/sedimentary
Sapphire (Blue/Violet Rough)
Corundum (Al2O3)
gemstone
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Quartzite (River Cobble)
Metamorphic Rock (composed predominantly of SiO2)
metamorphic
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
metamorphic
Weathered granite (likely with accessory quartz)
Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende
igneous
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Yellow Quartz
Silicon Dioxide (SiO2)
mineral
Likely milky quartz with iron-oxide inclusions
Quartz, silicon dioxide (SiO₂)
mineral
Basalt (Porphyritic Basalt)
Porphyritic Basalt (Mafic volcanic rock)
igneous
Weathered basaltic rock (probable basalt)
Basalt; fine-grained mafic silicate rock, commonly plagioclase + pyroxene ± olivine
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Feldspar (likely Amazonite or Plagioclase)
Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate
mineral
Epidote
Epidote - Ca2(Al,Fe)3(SiO4)3(OH)
metamorphic
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Granite
Intrusive igneous felsic rock
igneous
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Chert Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Weathered Pebble)
Arenite (composed primarily of SiO2)
sedimentary
Quartzite (likely Iron-stained)
SiO2 (Metamorphosed Sandstone)
metamorphic
Hag Stone (Holed Quartzite Pebble)
Quartzite (SiO2 based) with natural vug or erosion hole
sedimentary/metamorphic
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic plutonic igneous rock (SiO2 range 65-75%)
igneous