Foliated Metamorphic Rock (likely Gneiss or Schist)
Gneissic Metamorphic Rock
metamorphic
Category
Igneous And Metamorphic Derivative (Weathered)
Browse igneous and metamorphic derivative (weathered) specimens identified by the Rock Identifier community.
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
sedimentary
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
mineral
Red Granite
Felsic intrusive igneous rock (K-feldspar rich Granite)
igneous
Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
igneous
Mica-rich Pegmatite
Pegmatite (rich in Muscovite and Biotite)
igneous
Garnet Rhyolite
Rhyolite (high-silica volcanic rock) with almandine/spessartine garnet
igneous
Milky Quartz with Chlorite/Moss Infusions
Silicon Dioxide (SiO2)
mineral
Quartz (River Siltstone Quartzite Pebble)
Silicon Dioxide (SiO2)
metamorphic
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Mineral
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Mineral
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Copper-bearing Quartz (likely Chrysocolla or Malachite staining)
Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock
mineral
Quartz (Milky or Iron-stained)
Quartz (Silicon Dioxide, SiO2)
mineral
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Basalt with Iron Oxidation
Vesicular Basalt (Aphanitic Mafic Igneous Rock)
igneous
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Mineral
Ruby (Corundum)
Corundum (Aluminum Oxide with Chromium), Al2O3:Cr
mineral
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
mineral
Magnetite
Magnetite (Fe3O4)
mineral
Banded Gneiss
Gneiss (typically quartz, feldspar, mica, amphibole composition)
metamorphic
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Crystalline Quartz (Rough)
Quartz (Silicon Dioxide, SiO2)
mineral
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Mineral
Granite (specifically Rapakivi Granite)
Phaneritic Felsic Igneous Rock (Granite)
igneous
Pyrite (Iron Pyrite) with Goethite Oxidation
Iron Sulfide (FeS2)
mineral
Basalt Pebble with Epidote/Olivine
Vitreous Basalt (SiO2 with Ca/Mg/Fe silicates)
igneous
Artificial Rock Face (Faux Rock)
Glass Fiber Reinforced Concrete (GFRC)
man-made/construction material
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with hematite/limonite inclusions
mineral
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Chert (specifically Iron-stained or Jasperoid Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Gneiss
Gneiss (Metamorphic rock)
metamorphic
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Quartzite
Quartzite (primarily SiO2)
Metamorphic
Chert (Nodular Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Green Aventurine (likely)
Silicon dioxide (SiO2) with fuchsitemica inclusions
Mineral (specifically a variety of Quartz)
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Vesicular Basalt (Amygdaloidal)
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Banded Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily Quartzite and Feldspar grains)
sedimentary