Anthracite Coal
Anthracite
Category
Browse metamorphic (low grade) specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
Anthracite Coal
Anthracite
Blue Sapphire
Corundum (Al2O3)
Tiger's Eye
SiO2 (Quartz with inclusion of iron oxides)
Citrine Quartz Crystal Cluster
Silicon Dioxide (SiO2) with iron impurities
Quartz (Iron-Stained or Milky Quartz)
Silicon Dioxide (SiO2)
Serpentine
Antigorite, Lizardite, or Chrysotile; (Mg,Fe)3Si2O5(OH)4
Bornite
Copper Iron Sulfide (Cu5FeS4)
Marble
Crystalline Limestone (mostly CaCO3 / Calcium Carbonate)
Anthracite Coal
Anthracite (Carbon Content 86–97%)
Schist
Mica Schist
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Celadonite in Basalt (Green Earth)
Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
Ironstone Concretion
Siderite or Hematite Concretion
Jadeite Jade
Jadeite (Sodium Aluminum Silicate, NaAlSi₂O₆)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite (Carbon-based metamorphic rock, 86-97% C)
Gold Quartz (Auriferous Quartz)
Silicon Dioxide (SiO2) with trace Gold (Au) and Iron Oxides
Ruby (Rough/Raw)
Corundum (Al2O3:Cr)
Anthracite Coal
Anthracite
Greenschist
Greenschist facies rock
Raw Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Pink Sapphire
Corundum (Al2O3 with Chromium/Titanium/Iron traces)
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium impurities)
Siltstone
Siltstone (primarily composed of quartz and clay minerals)
Granitoid (Granite/Gneiss)
Granitoid silicate rock, primarily quartz and feldspar
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
Rough Sapphire
Corundum (Al2O3)
Sapphire Rough (Corundum)
Corundum (Aluminum Oxide, Al2O3)
Serpentinite
Serpentinite (complex silicate minerals including Mg3Si2O5(OH)4)
Emerald / Fluorite
Beryl (Be3Al2Si6O18) / Fluorite (CaF2)
Ruby (Corundum)
Al2O3 (Aluminium oxide with Chromium impurities)
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Jadeite
Jadeite (NaAlSi2O6)
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
Anthracite Coal
Anthracite
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Anthracite
Anthracite (Carbon)