Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
Category
Browse sedimentary or metamorphic derived specimens identified by the Rock Identifier community.
Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
Garnet Schist
Almandine-Muscovite Schist
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Quartzite River Stone
Quartzite (primarily SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Biotite Schist (likely)
Biotite Schist (rock), Biotite (mineral)
Sandstone, Quartzite, and River Pebbles
Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures
Jasper (likely a variety of Brecciated Jasper or a patterned variety)
Silicon dioxide (SiO2)
Quartz / Quartzite
Silicon Dioxide (SiO2)
Red Quartzite
Quartzite (SiO2)
Calcite
Calcium Carbonate (CaCO3)
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
Milky Quartz
Quartz (Silica / Silicon Dioxide, SiO2)
Pyrite
Iron Disulfide (FeS2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Rhodochrosite
Manganese carbonate (MnCO3)
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Quartzite (clastic/metamorphic subtype)
Quartzite (primarily Silicon Dioxide, SiO2)
Yellow Quartzite (or Quartz River Pebble)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Muscovite Mica (in Quartz matrix)
Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)
Labradorite (Carved)
(Ca, Na)(Al, Si)4O8
Citrine
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Specular Hematite
Specularite (Iron Oxide, Fe2O3)
Peach Moonstone (Orange/Peach Feldspar)
Potassium aluminum silicate (KAlSi3O8)
Banded Agate
Cryptocrystalline Silica (SiO2)
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with trace Iron (Fe)
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Jasper (likely Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with impurities