Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
Category
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily SiO2)
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
Quartz (River Siltstone Quartzite Pebble)
Silicon Dioxide (SiO2)
Lepidolite in Quartz (Obelisk)
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lepidolite)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Greywacke
Lithic wacke (variety of Sandstone)
River Cobble (Phyllite or Quartzite)
Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)
Muscovite Mica (with Quartz)
Muscovite (KAl2(AlSi3O10)(OH)2)
Sandstone (Quartzite Pebble)
Arenite (primarily SiO2)
Rhodonite
(Mn,Fe,Mg,Ca)SiO3
Milky Quartz
Silicon Dioxide (SiO2)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Sodalite
Sodalite [Na8(Al6Si6O24)Cl2]
Mica Schist
Mica Schist (predominantly Muscovite or Biotite)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Sandstone Concretion (Omar or Nut Rock)
Sedimentary Concretion (specifically an 'Omarolluk' or Omar)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Blue Calcite
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Yellow Ocher / Limonite
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Ironstone Concretion (Moqui Marble type)
Ferruginous Concretion (Fe2O3 / FeO(OH))
Chakra Stone Bracelet (mixed gemstones)
Multi-mineral/Gemstone assembly (primarily Quartz variety beads)
Granite (Phaneritic Igneous Rock)
Granite
Ferruginous Quartz
Iron-stained Quartz (SiO2 with Fe2O3 impurities)
Amethyst (Polished/Carved Crystal)
Silicon Dioxide (SiO2) with trace Iron (Fe)
Quartz (Crystal/Druzy Quartz)
Quartz (SiO₂)
Corundum (Ruby variety)
Aluminium oxide (Al2O3)
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
Quartzite (River Pebble)
Recrystallized Quartz (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Iron Ore (Limonite and Hematite)
Goethite/Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Quartz
Quartz (SiO₂)
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
Sandstone
Arenite
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Slate with Iron Staining
Low-grade Metamorphic Mudstone (Slate)