Andesite
Andesite
Category
Browse rock specimens identified by the Rock Identifier community.
Andesite
Andesite
Granite (Pink/Red)
Phaneritic Plutonic Felsic Rock (major minerals: Quartz, Orthoclase Feldspar, Plagioclase Feldspar)
Barite Rose (Desert Rose)
Barium Sulfate (BaSO4)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
River Stone (Quartzite/Siltstone mixture)
Silicon Dioxide (SiO2) based metamorphosed sandstone
Clear Quartz (Druzy)
Crystalline Silicon Dioxide (SiO2)
Pumice
Pumice (Vesicular volcanic glass)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
Crushed Granite Gravel
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase Feldspar)
Chert (Banded)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Red Quartzite
Quartzite (primarily SiO2)
Pumice
Pumicite (Amorphous Volcanic Glass)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Granodiorite
Granodiorite
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Pumice
Pumice (volcanic glass froth)
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Basalt
Basalt
Bauxite
Bauxite (Al2O3·2H2O)
Quartzite
Quartzite (Primary mineral: SiO2)
Gneiss (Banded Gneiss)
Gneiss
Quartzite
Quartzite (mainly SiO2)
Mica Schist
Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)
Pumice
Pumice (a highly vesicular volcanic glass)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
Quartzite
Quartzite (SiO2)
Lapis Lazuli
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
Sandstone (Ferruginous)
Arenite (with iron oxide cement)
Serpentine
Serpentine Group (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Eclogite
Eclogite
Basalt
Basalt (SiO2 percentage between 45% and 52%)
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
Pumice
Pumicite / Vesicular Rhyolite
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Bored Siltstone (Holey Rock)
Siltstone with Pholad borings (Lithophaga/Pholadidae trace fossils)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)