Mineral, Often Found In Metamorphic Rocks But Also In Sedimentary And Igneous Rocks

Bauxite

Bauxite (principal ore of aluminum, primarily Al(OH)3)

Hematite with Magnetite

Iron Oxide (Fe2O3)

Quartzite

Quartzite (primarily SiO2)

Sandstone with Quarzite clasts

Arenite (SiO2 based)

Sandstone (likely Calcareous or Quartz-rich)

Arenite (SiO2 based typically)

Dendritic Agate

Silicon Dioxide with inclusions (SiO2 + Mn/Fe)

Emerald (Rough)

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Quartzite

Quartzite (containing SiO2)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with Iron Oxide)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Chalcedony (Botryoidal Agate)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (SiO2)

Chalcedony (Moonstone-like Agate)

Silicon Dioxide (SiO₂)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)

Muscovite Schist

Mica Schist (primarily KAl2(AlSi3O10)(OH)2)

Mica Schist

Mica Schist (Complex Silicate Rock)

Blue Quartz with Dumortierite/Magnesio-riebeckite inclusions

Quartz (SiO2) containing Dumortierite (Al7(BO3)(SiO4)3O3)

Rough Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Sandstone

Arenite (predominantly SiO2 quartz grains)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Pyrite (on Quartz matrix)

Iron Sulfide (FeS2)

Sandstone (with banding)

Arenite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Rough Emerald (Beryl)

Emerald (Be3Al2(SiO3)6 with Cr/V impurities)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2 + K(Al,Cr)2AlSi3O10(OH)2

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Quartz Geode (partially opened)

Silicon Dioxide (SiO2) with iron staining

Milky Quartz

Silicon Dioxide (SiO2)

Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidote and Quartz)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Carnelian

Carnelian (Microcrystalline Quartz, SiO2)

Marble (Carrara style)

Recrystallized Calcite-rich Metamorphic Rock (CaCO3)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Garnet Schist

Almandine-Mica Schist

Sandstone

Arenite (SiO2 based)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Slate

Foliated Metamorphic Rock (composed mainly of clay minerals or micas)

Smoky Quartz in Matrix

Silicon dioxide (SiO2) within Pegmatite/Gneiss

Staurolite (Fairy Stone)

Staurolite (Fe2+2Al9Si4O23(OH))