Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Category
Sedimentary (Processed Mineral Product)
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Processed Mineral Product) in the encyclopedia
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Blue Quartzite (Dyed)
Silicon Dioxide (SiO2) with inclusions
metamorphic
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
igneous
Opal
Hydrous silicon dioxide (SiO2·nH2O)
mineral
Yellow Quartz (Chalcedony)
Quartz / Chalcedony (Silicon Dioxide, SiO2)
mineral
Man-made Dyed Aura Quartz
Silicon Dioxide (SiO2) with metallic coating/dye
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Chlorite/Epidote
Silicon Dioxide (SiO2) with phyllosilicate or sorosilicate inclusions
mineral
Mica Schist
Mica Schist (primarily Muscovite or Biotite Schist)
metamorphic
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Tiger's Eye
SiO2 (Silicon Dioxide with iron inclusions)
Mineral
Granite (Light-colored quartz/feldspar variety)
Granite (composed primarily of Quartz SiO2 and Feldspar KAlSi3O8)
igneous
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
Mixed Polished Gemstones (Tumbled Stones)
Mixed Silicates and Oxides (SiO2, KAlSi3O8, Ca2Al2Be3Si6O22, etc.)
mineral
Specular Hematite with Quartz
Ferric oxide (Fe2O3) and Silicon dioxide (SiO2)
Mineral
Black Onyx and Verdigris Copper Jewelry
Chalcedony (SiO2) with Copper Patina
mineral
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate Hydroxide - NaFe2+3Al6Si6O18(BO3)3(OH)3OH
mineral
Schist
Mica Schist
metamorphic
Greenstone
Greenschist
metamorphic
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Mineral
Aquamarine (Beryl)
Beryllium aluminum silicate (Be3Al2Si6O18)
mineral
Turquoise (beads)
Turquoise; CuAl6(PO4)4(OH)8·4H2O
Mineral
Quartz (Float/Abraded)
Quartz (SiO₂)
Mineral
Chert (specifically Red Chert/Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Gneiss
Gneiss (a rock type, not a specific mineral with a formula)
Metamorphic Rock
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheets with Quartz)
metamorphic
Quartz on Host Rock
Silicon Dioxide (SiO2)
mineral
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Pyrite and Fluorite on Quartz (Matrix Specimen)
Iron Disulfide (FeS2) and Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
metamorphic
Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Red Jasper
Microcrystalline Quartz (SiO2 with Iron Oxide impurities)
sedimentary
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2)
sedimentary
Black Tourmaline in Quartz Matrix
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
mineral
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Silver (Native Silver/Alloy Specimen)
Ag (Native Silver element), specifically a 90% Ag / 10% Cu alloy
mineral
Pink and Green Tourmaline (Tumbled)
Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4)
mineral
Gold Nugget
Native Gold (Au)
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
Gold Flakes
Native Gold (Au)
mineral