Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
metamorphic
Category
Sedimentary And Igneous (Mixed)
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
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White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Gravel variety)
Silicon Dioxide (SiO2)
mineral
Gneiss Pebble
Gneiss
metamorphic
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
sedimentary
Blue Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions
sedimentary
River Pebbles (Basalt and Graywacke/Limestone)
Mafic Volcanic Rock / Impure Sandstone
igneous and sedimentary
Rounded dark pebble, likely basaltic andesite
Fine-grained mafic volcanic rock; probable basalt or andesite, identification uncertain from image alone
igneous
Pyrite
Pyrite (FeS2)
Mineral
Smoky Quartz
Smoky Quartz (SiO ₂)
Mineral
Quartz-rich mineral fragment
Quartz (silicon dioxide, SiO₂), possibly milky quartz
mineral
Quartz–mica metamorphic rock, likely schist
Quartz–muscovite/biotite schist; predominantly SiO₂ quartz with phyllosilicate micas
metamorphic
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz with Iron Oxide Stain
Silicon Dioxide (SiO2) with Hematite/Limonite coatings
mineral
Gneiss
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Granite Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Foliated Gneiss (River-Worn Pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
Metamorphic
Hematite (Iron Ore)
Hematite (Fe2O3)
mineral
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Feldspathic Gneiss
Feldspathic Gneiss (High-grade regional metamorphic rock)
metamorphic
Milky Quartz (Crystal Cluster)
Silicon Dioxide (SiO2) - Quartz Variety
mineral
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
sedimentary or igneous
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Carnelian Agate
Silicon dioxide (SiO2) - variety of Chalcedony
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Quartz (likely tumbled or naturally water-worn)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
River Rock (Granitic Gneiss)
Foliated Granitic Gneiss
metamorphic
Quartz (specifically Milky Quartz/Quartzite)
Silicon Dioxide (SiO2)
Mineral
Folded Schist / Gneiss (Metamorphic Rock)
Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)
metamorphic
White Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Vesicular basalt (likely weathered lava rock)
Basalt; fine-grained mafic volcanic rock composed chiefly of plagioclase, pyroxene, and commonly olivine
igneous
Glacial granite/granitoid boulder
Granite to granodiorite; chiefly quartz, feldspar, and biotite/hornblende
igneous
Veined Quartz
SiO2 (Silicon Dioxide)
Mineral
Milky quartz (quartz-rich fragment)
Quartz, silicon dioxide (SiO₂)
mineral
Black River Stone (Chert or Basalt Pebble)
Microcrystalline Quartz (SiO2) or Mafic Igneous Rock
sedimentary