Gneiss
Gneiss
Category
Browse industrial byproduct (often confused with igneous rocks or meteorites) specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Amber Agate / Carnelian
Chalcedony (Silicon Dioxide, SiO2)
Yellow Chalcedony (likely carnelian or yellow agate)
Silicon Dioxide (SiO₂)
Blue-green copper mineral specimen, likely chrysocolla-bearing rock
Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with malachite or chrysocolla matrix
Milky Quartz
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Clear Quartz
Silicon Dioxide (SiO2)
Quartz pebble
Silicon dioxide (SiO2)
Yellow Quartz
Silicon Dioxide (SiO2)
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Sodalite
Chloric sodium aluminum silicate (Na8(Al6Si6O24)Cl2)
Smoky Quartz
SiO2 (Silicon Dioxide)
Quartz with Iron Stains
Silicon Dioxide (SiO2) with FeOx inclusions
Smoky Quartz
Quartz (Silicon Dioxide, SiO2)
Eudialyte with Syenite
Eudialyte: Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2
Quartz (Milky Quartz/Citrine Type)
Silicon Dioxide (SiO2)
Quartzite
Silicon Dioxide (SiO2)
Granite Gneiss
Gneiss (quartz-feldspar dominated)
Quartz Pebble
Silicon Dioxide (SiO2)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
Garnet Schist
Almandine-Garnet Mica Schist
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Chlorite or Actinolite
Greenstone
Metabasalt
Milky Quartz
Silicon Dioxide (SiO2)
Citrine or Yellow Quartz
Quartz (SiO2) with iron impurities
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Quartzite
Quartzite (SiO2)
Quartzite
Silica (SiO2)
Quartz Sand Grain
Silicon Dioxide (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (SiO2 + impurities)
Carnelian Agate
Silicon dioxide (SiO2) - Chalcedony variety
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Gneiss
Gneiss
Quartzite
Metamorphosed sandstone (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)