Rough Emerald
Beryl (Be3Al2Si6O18 with Chromium and Vanadium impurities)
mineral
Category
Sedimentary Or Metamorphic (Low Grade)
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Learn about Sedimentary Or Metamorphic (Low Grade) in the encyclopedia
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Chalcopyrite in Quartz (Gold Ore Matrix)
CuFeS2 (Chalcopyrite) with SiO2 (Quartz)
mineral
Cordierite (Iolite) in Quartz
Cordierite (Magnesium iron aluminium cyclosilicate) - Mg2Al4Si5O18
metamorphic
Quartzite
Silicon Dioxide (SiO2)
metamorphic
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
metamorphic
Pearl-embellished decorative cross
Pearl (biogenic calcium carbonate, predominantly aragonite) with rhinestone-mounted glass or synthetic gemstones
gemstone
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst (Rough)
Quartz, SiO2
mineral
Tree Agate
Chalcedony (SiO2)
gemstone
Green Tourmaline
Elbaite - Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
mineral
Smoky Quartz
Silicon dioxide (SiO2)
mineral
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
mineral
Coal (Anthracite or Bituminous)
Carbonaceous sedimentary rock (Carbon)
sedimentary
Corundum (Sapphire in Host Rock)
Corundum (Aluminum Oxide, Al2O3)
mineral
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Dyed blue howlite (turquoise imitation), possibly dyed magnesite
Howlite: Ca₂B₅SiO₉(OH)₅; the vivid blue color is artificial dye. Exact identification is uncertain from the photograph alone.
gemstone
Quartzite Pebble
Metamorphosed Silicon Dioxide (SiO2)
metamorphic
Schist
Mica Schist (predominantly Muscovite or Biotite)
metamorphic
Lapis Lazuli
Complex silicate rock containing lazurite, calcite, and pyrite
mineral
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
sedimentary
Chalcedony
Silicon Dioxide (SiO2)
mineral
Lapis Lazuli
Lapis Lazuli (Rock containing Lazurite, Calcite, and Pyrite)
metamorphic
Quartz Vein in Matrix
Silicon Dioxide (SiO2)
mineral
Blue Sapphire
Corundum (Al2O3)
mineral
Rough Diamond
Diamond (C)
mineral
Diamond
Native Carbon (C)
mineral
Raw Diamond
Diamond (pure Carbon, C)
mineral
Rough Emerald
Beryl (Be3Al2(SiO3)6 with Chromium/Vanadium impurities)
mineral
Likely serpentine pebble
Serpentinite; predominantly serpentine-group minerals, Mg₃Si₂O₅(OH)₄
metamorphic
White calcite (likely tumbled calcite or marble fragment)
Calcite, calcium carbonate (CaCO₃); if the specimen is granular and rock-like, it may be marble, a calcite-rich metamorphic rock
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Botryoidal Chalcedony (Agate/Desert Rose Chalcedony)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Mineral
Quartz-rich rock, possibly milky quartz or quartzite
Quartz (silicon dioxide, SiO₂); if granular and foliated, likely quartzite
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Quartz (Rutilated)
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
mineral
Mica Schist
Mica Schist (Composition typically includes Muscovite KAl2(AlSi3O10)(OH)2 and Quartz SiO2)
metamorphic
Sandstone concretion (Ironstone-stained)
Arenite with Limonite/Hematite staining (Silica-based with Iron Oxides)
sedimentary
River Rock (Sandstone or Quartzite)
Clastic Sedimentary Rock / Quartzite
sedimentary
Muscovite (Mica)
Muscovite - KAl2(AlSi3O10)(OH)2
Mineral
Moss Agate
Silicon Dioxide (Chalcedony variety)
mineral