Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Category
Mineral Health
Browse mineral health specimens identified by the Rock Identifier community.
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Banded Gneiss (Variety of Gneiss)
Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)
Metamorphic Rock
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Orthoclase Feldspar (Potassium Feldspar)
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Fossilized Gastropod / Coral
Phylum Mollusca / Cnidaria (Silicified or Calcified)
fossil
Unidentified dark metallic sulfide specimen
Possibly pyrite-, chalcopyrite-, or galena-bearing ore; exact identification requires testing
mineral
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
mineral
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Limonite / Ironstone
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
Unknown Rock Fragment
Unknown
unknown
Magnetite
Fe3O4 (Iron(II,III) oxide)
mineral
Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Microcline Feldspar (Amazonite or White Feldspar)
KAlSi3O8
mineral
Native Copper
Copper (Cu)
mineral
Yellow Ochre / Limonite
Hydrated ferric oxide (FeO(OH)·nH2O)
mineral
Drill Core Samples (Varied Lithology)
Multi-lithological core samples (containing potential granite, marble, and phyllite/schist sequence)
igneous, sedimentary, and metamorphic
Granite
Granite (composed of Quartz, Feldspar, and Mica)
igneous
Magnetite (Lodestone)
Iron(II,III) oxide (Fe3O4)
mineral
Gypsum (Selenite sand)
Calcium sulfate dihydrate (CaSO4·2H2O)
mineral
Ruby (Raw Corundum)
Al2O3 (Aluminum Oxide)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Sandstone
Sandstone (composed primarily of sand-sized minerals or rock grains)
sedimentary
Fluorite (Fluor-spar)
Calcium Fluoride (CaF2)
mineral
Fluorite with Quartz
Fluorite (CaF2) and Quartz (SiO2)
mineral
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
mineral
Rainbow Fluorite
Calcium Fluoride (CaF2)
mineral
Granite
Granite
Igneous
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Quartz in Limonite-rich Matrix
Silicon Dioxide (SiO2) with Goethite/Limonite FeO(OH)·nH2O
Mineral in Sedimentary/Secondary host
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Goethite
mineral
Granite
Phaneritic Felsic Igneous Rock
igneous
Fluorite (Rainbow, Purple-Blue Tumbled)
Calcium Fluoride (CaF2)
Mineral
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Tumbled Mixed Gemstones and Rocks
Various mineral species including quartz (SiO2) and silicate minerals
mineral
Black Sand (Magnetite/Heavy Mineral Concentrate)
Magnetite-rich Placers (Fe3O4)
sedimentary
Raw greenish-blue quartz-bearing mineral specimen
Likely fluorite or chalcedony/quartz; exact identification requires hardness and crystal tests
mineral
Blue apatite specimen
Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F)
mineral