Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
Category
Browse mineral in metamorphic rock specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
Granitoid Gneiss with Feldspar Vein
Gneiss (High-grade Metamorphic Rock) with Potassium Feldspar (KAlSi3O8)
Quartzite Cobble
Metamorphic rock primarily composed of Quartz (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Muscovite Mica Schist
Metamorphic rock rich in muscovite mica (KAl2(AlSi3O10)(F,OH)2)
Serpentine / Serpentinite (with Weathering Crust)
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Glacial Cobbles (predominantly Granite and Gneiss)
Mixed lithologies (Quartz, Feldspar, Mica assemblage)
Crushed Granite and Basalt
Phaneritic Igneous Rock / Aphanitic Igneous Rock
Greenstone (Prase / Metavolcanic)
Metamorphosed volcanic rock (Greenstone)
Unakite
Epidotized Granite
Unakite
Epidotized Granite
Mixed Gemstone Bracelet
Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)
Greenstone (likely serpentinite or chlorite-rich metamorphic rock)
Probable serpentinite/chlorite schist; commonly dominated by serpentine-group minerals, chlorite, talc, and magnetite
Quartzite
Quartzite
Kyanite
Kyanite (Al2SiO5)
Druzy Quartz on Limestone
Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Ruby (Corundum)
Aluminum oxide (Al2O3) with Chromium traces
Quartzite
Metamorphic rock predominantly composed of Quartz (SiO2)
Eclogite
Eclogite (Omphacite-Garnet Metamophic Rock)
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Quartz-rich rock, likely milky quartz or quartzite
Quartz (SiO₂); possibly quartzite, a recrystallized quartz sandstone
Emerald
Beryl (Be3Al2(SiO3)6)
Yellow Quartzite
Quartzite (SiO2)
Tumbled pale greenish stone, likely serpentine or altered limestone
Probable serpentine-group rock (antigorite/lizardite), possibly serpentinite; identification is visual only
Quartz-bearing iron-rich rock, possibly quartzite or hydrothermal breccia
Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite; exact host rock is uncertain from the photograph
Serpentinite
Serpentinite (complex silicate of magnesium, (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite
Quartzite
SiO2 (Silicon Dioxide)
Quartzite (Tumbled)
Recrystallized Quartz (SiO2)
Quartzite
Quartzite (SiO2)
Green Quartzite
Metamorphic rock primarily composed of Silicon Dioxide (SiO2) with mineral inclusions like fuchsite or chlorite
Weathered quartz-rich rock, likely milky quartz or quartzite
Quartz (SiO₂), possibly quartzite with iron-oxide staining
Schist (Garnet-Mica Schist)
Garnetiferous Mica Schist (primarily Muscovite/Biotite and Almandine Garnet)
Lapis Lazuli
Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)
Quartzite (River Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Quartz Vein in Host Rock
Crystalline Silicon Dioxide (SiO2) in Pelitic or Shaly Matrix