Gneiss
Gneiss
Category
Browse mineral based human made alloy specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Lepidolite (Tumbled)
K(Li,Al)3(Al,Si,4O10)(F,OH)2
Basalt with vesicles/amygdules
Basalt (containing volcanic glass and plagioclase)
Labradorite
(Ca,Na)(Al,Si)4O8 (Sodic-calcic plagioclase feldspar)
White Topaz
Al2SiO4(F,OH)2
Pink Granite
Phaneritic Plutonic Rock (Felsic)
Schist
Mica Schist (primarily Muscovite and Biotite)
Schist
Mica Schist
Quartz with Tourmaline inclusions
Silicon Dioxide (SiO2) with Tourmaline needles
Graphite
Graphite (Carbon, C)
Granite
Granite (phaneritic intrusive felsic igneous rock)
Basalt with Secondary Mineralization (Likely Zeolites or Calcite)
Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)
Dyed Agate
Silicon Dioxide (SiO2) - variety Chalcedony
Basalt with Quartz/Calcite Veining
Basalt (principally Plagioclase and Pyroxene)
Iron Slag
Ferrous Slag (Silicate/Oxide mixture)
Pink Granite (with Potassic Feldspar and Quartz)
Felsic Intrusive Igneous Rock (Granite)
Banded Agate (specifically Carnelian Agate)
Silicon dioxide (SiO2) - Chalcedony variety
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Granitoid (Granite/Gneiss mix)
Granite or Granitic Gneiss (Silicon dioxide SiO2 with Al, K, Na silicates)
Basalt with Epidote
Mafic volcanic rock with Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Granite
Phaneritic plutonic rock (SiO2 + Al2O3)
Desert Varnish on Sandstone
Ferromanganese coating on Quartz Arenite
Quartz Mica Schist
Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Banded Agate
Agate (chalcedony variety of Silicon Dioxide, SiO2)
Fire Agate (Crackle Agate)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Iron-Nickel Meteorite fragment
Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))
Schist
Mica Schist (formula variable based on mineral content, typically containing [K,Al,Fe,Mg,Si,O,H])
Mica schist
Schist (rich in Muscovite or Biotite mica)
Chert with Druzy Quartz and Mossy/Iron Inclusions
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Chert (Green variety)
Microcrystalline Quartz (SiO2)
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)