Biotite (Black Mica)
K(Mg,Fe)3AlSi3O10(OH,F)2
Category
Browse metamorphic (pseudo igneous) specimens identified by the Rock Identifier community.
Biotite (Black Mica)
K(Mg,Fe)3AlSi3O10(OH,F)2
Pyrite in Matrix
Iron Sulfide (FeS2)
Garnet (Almandine)
Almandine Garnet (Fe3Al2(SiO4)3)
Green Aventurine
Silicon Dioxide (SiO2) with Chromium-rich Fuchsite mica
Tumbled blue stone, possibly sodalite or blue quartz
Indeterminate from the photograph; possibilities include sodalite (Na₈Al₆Si₆O₂₄Cl₂) or blue quartz (SiO₂)
Magnetite / Iron Ore
Magnetite (Fe3O4)
Biotite Mica Schist
Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2
Feldspar (Microcline / Orthoclase)
Potassium Feldspar (KAlSi3O8)
Clear Quartz (Faceted)
Silicon Dioxide (SiO2)
Quartz (Tumbled)
SiO2 (Silicon Dioxide)
Quartz (Citrine or Iron-Stained)
SiO2
Quartz pebble
Silicon dioxide (SiO2)
Citrine
Silicon dioxide (SiO2)
Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)
Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)
Apatite
Ca5(PO4)3(F,Cl,OH)
Clear Quartz
Silicon Dioxide (SiO2)
Blue Apatite
Apatite Group (Ca5(PO4)3(F,Cl,OH))
Quartz fragment
Silicon Dioxide (SiO2)
Blue Apatite
Ca5(PO4)3(F,Cl,OH)
Greenschist
Greenschist (containing Chlorite, Actinolite, and Epidote)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock)
Epidotized Metamorphic/Igneous Rock
Sodalite
Sodalite, Na8(Al6Si6O24)Cl2
Likely garnet crystal
Garnet-group silicate; species cannot be determined from the image
Weathered rock fragment (likely granite or granitic gneiss)
Undetermined felsic rock; possibly quartz–feldspar granite
Fossiliferous limestone fragment
Calcitic limestone; mainly calcium carbonate (CaCO₃), possibly with shell or coral debris
Foliated metamorphic rock, likely mica schist
Mica schist, mainly quartz–feldspar–mica assemblage
Magnetite / Ironstone
Magnetite (Fe3O4)
Muscovite Mica
KAl2(AlSi3O10)(OH)2
Moonstone (Feldspar)
Orthoclase or Oligoclase (KAlSi3O8)
Garnet (Almandine/Pyrope series)
Silicate mineral (Almandine: Fe3Al2Si3O12; Pyrope: Mg3Al2Si3O12)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Likely quartz-bearing rock fragment
Quartz (SiO₂), possibly with iron-oxide staining or other mineral inclusions
Milky quartz
Quartz, silicon dioxide (SiO₂)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Raw and Water-worn)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Magnetite
Fe3O4 (Iron(II,III) oxide)
Quartz with Muscovite Mica
Silicon Dioxide (SiO2) with Potassium aluminum silicate hydroxide fluoride [KAl2(AlSi3O10)(F,OH)2]
Milky Quartz with inclusions
Silicon Dioxide (SiO2)