Metamorphic (Low Grade)

Browse metamorphic (low grade) specimens identified by the Rock Identifier community.

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

metamorphic

Marble

Recrystallized Calcite (CaCO3)

metamorphic

Green Aventurine

Quartzite (variety Aventurine) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)

metamorphic

Nephrite Jade (River Bed Pebble)

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

metamorphic

Orthoclase Feldspar

KAlSi3O8 (Potassium aluminum silicate)

mineral

Schorl (Black Tourmaline)

Sodium Iron Aluminum Borosilicate Hydroxide; NaFe2+3Al6Si6O18(BO3)3(OH)3OH

mineral

Moonstone (specifically Rainbow Moonstone / White Labradorite)

White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)

mineral

Mica (Muscovite)

Muscovite, KAl2(AlSi3O10)(OH)2

Mineral

Biotite Schist

Metamorphic

Labradorite (Feldspar)

Labradorite: (Ca,Na)(Al,Si)4O8

mineral

Specularite (Specular Hematite)

Iron Oxide (Fe2O3)

mineral

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

mineral

Pyrite (Cube variety)

Iron Sulfide (FeS2)

mineral

Potassium Feldspar

Orthoclase (KAlSi3O8)

mineral

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

mineral

Clear Quartz Crystal

Silicon Dioxide (SiO2)

mineral

Nephrite (a form of Jade)

Nephrite (a variety of the mineral actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)

Mineral

Clear Quartz

Silicon Dioxide (SiO2)

mineral

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)

mineral

Clear Quartz Crystal

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Mineral

Milk Quartz (Vein Quartz)

Quartz (Silicon Dioxide, SiO2)

mineral

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Mineral

Blue Sapphire (Synthetic or Man-made Glass Imitation)

Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic

mineral

Yellow Quartzite (Tumbled)

Quartzite (SiO2)

metamorphic

Anthracite Coal

Anthracite (Carbon-rich Sedimentary-to-Metamorphic Rock)

metamorphic

Moonstone (specifically White Moonstone/Adularia)

Potassium aluminum silicate ((K,Na)AlSi3O8)

mineral

Blue Sapphire

Corundum (Al2O3 with trace amounts of iron and titanium)

mineral

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

mineral

Clear Quartz

Silicon Dioxide (SiO2)

mineral

Smoky Quartz

Silicon Dioxide (SiO2)

mineral

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)

metamorphic

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Aquamarine

Beryl (Be3Al2Si6O18 with Fe2+ impurities)

mineral

Olivine (often within Peridotite)

Magnesium iron silicate, (Mg,Fe)2SiO4

mineral

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities and natural radiation

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Black Tourmaline (Schorl)

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH

mineral

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Green Quartz (Prasiolite variant or Aventurine)

Silicon Dioxide (SiO2)

mineral