Gneiss
Gneissic Metamorphic Rock
Category
Browse mineral, often found as a rock (metamorphic) specimens identified by the Rock Identifier community.
Gneiss
Gneissic Metamorphic Rock
Olivine (Peridot)
Olivine (Mg, Fe)2SiO4
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
Flower Agate
Chalcedony (SiO2) with Scolecite/Opaque inclusions
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Garnet
Almandine (Fe3Al2(SiO4)3)
Marble
Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amphibolite with Hornblende
Amphibole-rich Metamorphic Rock (Ca2(Mg,Fe)5Si8O22(OH)2)
Chrysoprase
Chalcedony (cryptocrystalline silica containing nickel); Chemical Formula: SiO2 with Ni impurities
Chert (specifically Black Chert or Flint)
Cryptocrystalline Quartz (SiO2)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
Gneiss (High-Grade Metamorphic Rock)
Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)
Granitic Gneiss
Gneiss (Metamorphic rock of granitic composition)
Quartz
Silicon Dioxide (SiO2)
Agate
Banded Chalcedony (SiO2 - Silicon Dioxide)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (SiO2)
Lapis Lazuli
Na8[Al6Si6O24]S2 (Lazurite component), a rock composed primarily of Lazurite, Calcite, and Pyrite
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
Hypersthene
Hypersthene (formula: (Mg,Fe)SiO3)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Schist
Mica Schist
Serpentinite
Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
Banded Agate (specifically Lace Agate type)
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
Smoky Quartz
Silicon Dioxide (SiO2)
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
Green Aventurine in Host Rock
SiO2 (Quartz with Fuchsite inclusions)
Magnetite / Ironstone
Magnetite (Fe3O4)
Schist
Mica Schist
Chert
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (primarily SiO2)
Garnet Schist
Almandine Garnet-Mica Schist (X₃Y₂(SiO₄)₃)
Chert (often called Flint when dark)
Microcrystalline silicon dioxide (SiO2)