Sillimanite
Al2O3(SiO2)
mineral
Category
Mineral Specimen
Browse mineral specimen specimens identified by the Rock Identifier community.
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Cavansite
Cavansite (Ca(VO)Si4O10·4H2O)
mineral
Milky quartz cluster
Quartz (silicon dioxide, SiO₂), likely druzy or microcrystalline quartz
mineral
Tumbled pale green calcite
Calcite (CaCO₃)
mineral
Hematite (Specularite)
Fe2O3 (Iron(III) oxide)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Smoky Quartz (with Hematite inclusions)
Silicon Dioxide (SiO2)
mineral
Green Tourmaline
Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4)
mineral
Amazonite
Potassium Feldspar (Microcline) - K(AlSi3O8)
mineral
Amethyst
Silicon dioxide (SiO2) containing traces of iron and manganese
mineral
Labradorite
(Ca, Na)(Al, Si)4O8
mineral
Watermelon Tourmaline
Elbaite - Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3OH
mineral
Amethyst (Quartz)
Silicon Dioxide with Iron impurities (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Citrine
Citrine (Silicon Dioxide - SiO2)
mineral
Geodal Limestone / Calcite Druze
Calcium Carbonate (CaCO3)
sedimentary
White Opal
Hydrated Silica (SiO2·nH2O)
mineral
Pegmatite with quartz, feldspar, mica, and tourmaline
Granitic pegmatite; chiefly quartz (SiO₂), feldspar, muscovite, and black schorl tourmaline (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
igneous
Coal (Bituminous / Anthracite)
Organic Sedimentary Rock (Carbonaceous Rock)
sedimentary
Emerald (Rough)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
gemstone
Corundum (Sapphire variant)
Aluminium oxide (Al2O3)
mineral
Black Obsidian
Volcanic Glass (SiO2 with impurities)
igneous
Pyrite
Iron Sulfide (FeS2)
mineral
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
mineral
Amazonite
Potassium Feldspar (KAlSi3O8)
mineral
Pink-and-gray quartz-rich pegmatite, possibly rose quartz with feldspar
Quartz (SiO₂) with K-feldspar/plagioclase; likely pegmatitic granite
igneous
Prehnite
Prehnite Ca2Al2Si3O10(OH)2
mineral
Muscovite mica
Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂
mineral
Serpentine (variety: Serpentine Rock)
Antigorite, Lizardite, or Chrysotile; formula generally (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
Quartz pebble
Silicon Dioxide (SiO2)
mineral
Blue Dumortierite Quartz
Dumortierite in Quartz (AlAl6BSi3O12(O,OH)3)
mineral
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
mineral
Raw calcite specimen
Calcite, calcium carbonate (CaCO₃)
mineral
Fluorite (Durango Fluorite)
Calcium Fluoride (CaF2)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Nickel
Nickel (Ni)
mineral
Beryl (Emerald Variety)
Beryllium Aluminum Silicate (Be3Al2(SiO3)6)
mineral
Pyrite and Quartz Agglomerate
Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)
mineral
Limonite Nodules / Goethite
Hydrated Iron Oxide-Hydroxide (FeO(OH)·nH2O / Fe2O3·nH2O)
mineral
Chert with Druzy Quartz Geode
Microcrystalline Quartz (SiO2)
sedimentary