Mica Schist or Muscovite
KAl2(AlSi3O10)(OH)2
Category
Browse mineral (pseudomorph) specimens identified by the Rock Identifier community.
Mica Schist or Muscovite
KAl2(AlSi3O10)(OH)2
Limonite with Gossan / Iron Ore
Hydrated iron oxide-hydroxide, approximately FeO(OH)·nH2O
Graphite
Graphite (Carbon, C)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(F,OH)2)
Specular Hematite
Hematite (Fe2O3)
Ironstone / Hematite
Iron(III) oxide (Fe2O3)
Celestite
Celestine (SrSO4)
Graphite
Graphite (Carbon, C)
Galena with Pyrite
Lead Sulfide (PbS) associated with Iron Sulfide (FeS2)
Feldspar
Triclinic or Monoclinic Tectosilicate (e.g., KAlSi3O8)
Chalcopyrite
CuFeS2
Hematite
Hematite (Fe2O3)
Muscovite
KAl2(AlSi3O10)(OH)2
Pyrite
Iron Sulfide (FeS2)
Fluorite
Calcium fluoride (CaF2)
Sandstone
Sandstone (composed primarily of sand-sized minerals or rock grains)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Rounded, weathered stone (likely basaltic or andesitic river cobble)
Fine-grained mafic to intermediate volcanic rock; exact identification requires examination of a fresh surface
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Granite pebble
Granite; predominantly quartz, feldspar, and mica
Quartz crystal cluster
Quartz (silicon dioxide, SiO₂), likely milky or druzy quartz
Small brown mineral or rock fragment
Undetermined; the image does not show enough detail for reliable identification
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Amygdaloidal Basalt with Quartz Veining
Basalt (Extrusive Igneous Rock) with Quartz (SiO2) veining
Gneiss
Gneiss (foliated metamorphic rock)
Granite with Mafic Xenolith
Intrusive Igneous Rock (Felsic to Intermediate)
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Granite
Granite (Felsic Plutonic Rock)
Basalt with an orange mineral vein
Fine-grained basalt, likely containing iron-stained calcite or zeolite; exact identification requires testing
Blue apatite specimen
Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F)
Granite
Phaneritic Felsic Igneous Rock
Microcline Feldspar (Amazonite or White Feldspar)
KAlSi3O8
Epidote
Epidote (Ca2(Al, Fe)3(SiO4)3(OH))
K-Feldspar (Potassium Feldspar)
Orthoclase / Microcline (KAlSi3O8)
Microcline Feldspar
KAlSi3O8
Graphite
Graphite (Carbon, C)
Pyrite
Iron Sulfide (FeS2)
Limonite
FeO(OH)·nH2O
Muscovite
Muscovite (KAl2(AlSi3O10)(OH)2)
Calcite
Calcium Carbonate (CaCO3)
Malachite-bearing Rock
Cu2CO3(OH)2
Copper Ore / Altered Granodiorite
Cupriferous rock with silicate gangue