Quartz
Silicon Dioxide (SiO2)
Category
Browse metamorphic or igneous specimens identified by the Rock Identifier community.
Quartz
Silicon Dioxide (SiO2)
Quartz Crystal
Silicon Dioxide (SiO2)
Quartz (Pink/Rose Quartz or Quartz Crystal)
Silicon Dioxide (SiO2)
Black Tourmaline
Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)
White Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Quartz with Mica/Host Rock
Silicon Dioxide (SiO2) with Phyllosilicates
Pyrite in Matrix (Gold-colored Chalcopyrite or Pyrite)
Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)
Pyrite
Iron Sulfide (FeS2)
Quartz (Milky/Crystalline fragment)
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Likely polished/tumbled dark mineral or glassy rock fragment
Indeterminate from image; possibly hornblende, schorl tourmaline, or obsidian
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Tiny amber-colored crystal fragment
Indeterminate; possibly quartz, feldspar, mica, or a sulfide mineral
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Rough Citrine Quartz
Citrine (Silicon Dioxide, SiO2 with iron impurities)
Garnet (likely Almandine or Pyrope)
Garnet (Group Name), Fe3Al2(SiO4)3 or Mg3Al2(SiO4)3
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
Muscovite
KAl2(AlSi3O10)(OH)2
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
Biotite / Black Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
Silicified oyster fossil
Fossil oyster shell, commonly Ostrea or Crassostrea, replaced or encrusted by chalcedony/quartz
Milky quartz pebble
Quartz (silicon dioxide, SiO₂)
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Weathered schist or gneiss fragment
Quartz–feldspar–mica metamorphic rock; likely mica schist or gneiss
Small quartz-rich pebble or rock fragment
Quartz (silicon dioxide, SiO₂), possibly with iron-oxide staining or host-rock inclusions
Muscovite mica
Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
Plagioclase Feldspar (specifically Albite/Oligoclase)
(Na,Ca)(Si,Al)4O8
Foliated Gneiss
Gneiss (Metamorphic Rock)
Gneiss
Foliated Metamorphic Gneiss
Gneiss
Gneissic Metamorphic Rock
Magnetite
Magnetite (Fe3O4)