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Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Banded Agate (specifically Carnelian Agate color)

Silicon Dioxide (SiO2) - variety of Chalcedony

Pyrite in Quartz (Drill Core)

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2) inclusions

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Feldspar, and Mica)

Chrysocolla in Matrix

Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix

Basalt with Vesicles

Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Limonitic Scoria (Vesicular Basalt with Iron Staining)

Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]

Amethyst (Faceted)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Arsenopyrite in Quartz Matrix

Arsenopyrite (FeAsS)

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Mixed Gemstone Beaded Jewelry

Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)

Green Tourmaline

Verdelite (Silicate mineral); Na(Li,Al)3Al6(BO3)3Si6O18(OH)4

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Quartz Crystal

Quartz (SiO₂)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Sandstone

Arenite (Siliclastic Sedimentary Rock)

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)

Limonite and Goethite encrusted Chert/Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)

Granite (specifically Pink Granite)

Phaneritic Plutonic Rock (High Potassium Feldspar Granite)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals, (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Optical Calcite

Calcite (Calcium Carbonate, CaCO3)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)

Granite

Granite

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Pumice (likely)

Pumice (extrusive igneous rock)

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)

Quartz (SiO₂)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)

Quartz Vein in Host Rock (Gneiss/Schist)

Silicon Dioxide (SiO2) within a metamorphic matrix

Black Tourmaline (Schorl)

Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Granite (tumbled pebble)

Granite (Plutonic Igneous Rock)

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite inclusions

Banded Iron Formation (BIF) with Quartz

Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)

Gneiss (Pebble)

Gneiss

Amygdaloidal Basalt with Secondary Minerals

Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)

Petrified Wood

Silicified Wood (SiO2)

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)