Gneiss
Gneiss
metamorphic
Community gallery
All rocks & minerals
Every specimen the Rock Identifier community has discovered, from desert agates to deep-sea basalts.
Gneiss
Gneiss
metamorphic
Quartz / Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Stalagmite (Flowstone)
Speleothem (Calcium Carbonate, CaCO3)
sedimentary
Yellow Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite (River Stone)
Quartzite (SiO2)
metamorphic
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Flint
Chert (SiO2)
sedimentary
Sandstone with Trace Fossils
Arenite with Ichnofossils
sedimentary
Fossilized Bored Limestone
Limestone with Ichnofossils (Gastrochaenolites or Entobia)
sedimentary
Vesicular Basalt River Cobble
Vesicular Basalt
igneous
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Boulder Opal
Hydrated amorphous silica (SiO2·nH2O) in ironstone matrix
mineral
Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Granite
Granitoid (dominated by Quartz and Feldspar)
igneous
Chert (White Variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Iron Staining)
Arenite (SiO2 predominantly)
sedimentary
Granite
Phaneritic Plutonic Felsic Rock (Granite)
igneous
Chert (Jasper/Common Opal transition)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
sedimentary
Basalt with Quartz Veins
Aphanitic Mafic Igneous Rock (Main body: SiO2, Fe, Mg rich)
igneous
Sandstone with Iron Oxide Staining
Arenite with Limonite/Hematite alteration
sedimentary
Sandstone (Iron-stained)
Arenite (primarily Quartz, SiO2)
sedimentary
Chert Nodules
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint/Jasper)
Silicon dioxide (SiO2) - Microcrystalline quartz
sedimentary
Basalt
Extrusive mafic igneous rock
igneous
Basalt
Basalt
igneous
Chert (Flint)
Chert (Cryptocrystalline Silicon Dioxide, SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Basalt
Aphanitic Mafic Igneous Rock
igneous
Pink Granite
Granite (Felsic intrusive igneous rock)
igneous
Red Quartzite
Metamorphic Quartzite (predominantly SiO2 with iron oxide impurities)
metamorphic
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt River Stone
Aphanitic Basalt
igneous
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2)
mineral
Granite (River Pebble)
Phaneritic Felsic Igneous Rock
igneous
Biotite Schist
Biotite-rich Schist
metamorphic
Quartzite River Stone
Metamorphic Quartzite (primarily SiO2)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Quartzite (Iron-Stained)
Quartzite (SiO2 with Fe2O3 inclusions)
metamorphic