Gneiss
Gneiss
Category
Browse mineral, part of a rock specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Gneiss (specifically a Banded Gneiss cobble)
Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)
Granite (Weathered)
Plutonic Igneous Rock (Granitic)
Granite
Granite (Silicic Plutonic Rock)
Amygdaloidal Rhyolite (often called Lake Superior Agate relative)
Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Flower Agate (Cherry Blossom Agate)
Chalcedony (Silicon Dioxide) with Opaque Inclusions - SiO2
Smoky Quartz (Tumbled)
Smoky Quartz (SiO2 - Silicon Dioxide)
White Topaz
Topaz [Al2SiO4(F,OH)2]
Flower Agate
Chalcedony with Opaque Spherulitic Inclusions (SiO2)
Pickled Dragon Eggs (Fictional Interpretation: Purple Agate or Amethyst Geodes)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz Pebble (Milky Quartz)
Silicon Dioxide (SiO2)
Blue Lace Agate (Polished Point)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
White Precious Opal
Hydrated Silica (SiO2·nH2O)
Quartz Geode
Silicon Dioxide (SiO2)
Pink Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Shale creek bed
Shale (fine-grained clastic sedimentary rock)
Garnet (almandine or pyrope variety)
Silicate mineral Group: (Fe, Mg, Mn, Ca)3(Al, Fe, Cr)2(SiO4)3
Amethyst Lace Agate / Banded Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Carnelian Agate
Carnelian (SiO2 with iron oxide impurities)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
Iron Slag (Industrial Byproduct)
Anthropogenic Vitrification Product/Ferrous Slag
Conglomerate
Conglomerate (clastic sedimentary rock)
Slate
Slate (Foliated Metamorphic Rock)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite, Sodalite, Calcite, and Pyrite)
Orthoclase Feldspar (Salmon variety)
Orthoclase, KAlSi3O8
Basalt (Vesicular)
Vesicular Basalt
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO₂)
Druzy Agate (Star-cut Geode Slice)
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline Quartz
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese