Tektite (Natural Glass)

Quartzite (Quartz Vein)

SiO2 (Silicon Dioxide)

Sandstone

Sedimentary Rock (Quartz Arenite)

Beach Pebble Quartzite / Chalcedony Pebble

Silicon Dioxide (SiO2)

Amethyst

Silicon dioxide (variant with ferric iron impurities), SiO2

Dyed Quartz Crystals

Silicon Dioxide (SiO2) with artificial pigment

Pink Quartzite

Metamorphosed Quartz Arenite (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Tumbled amethyst with possible lepidolite/colored quartz companion

Amethyst, purple quartz (SiO₂), likely with iron-related color centers

Yellow Quartz / Citrine Quartz

Silicon Dioxide (SiO2)

Nephrite Jade (Yellow Skin)

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Amethyst cluster

Quartz, SiO₂, violet variety (amethyst)

Sandstone

Arenite

Black Tourmaline (Schorl)

NaFe2+3Al6(BO3)3Si6O18(OH)4 (Schorl)

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Iron-Stained Quartz (Red/Hematoid Quartz)

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Smoky Quartz

Silicon Dioxide (SiO2)

Green Slag Glass

Amorphous Silica Glass (Anthropogenic)

Sandstone

Arenite

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Black Freshwater Pearls

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Ruby (Raw Corundum)

Alumina (Al2O3) with Chromium traces

Strawberry Quartz (Hematoid Quartz)

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)

Quartzite

Metamorphic Quartzite (SiO2)

Clear Quartz (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Purple Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based clastic rock)

Yellow Quartz (Citrine-colored Quartz)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon dioxide (SiO2)

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Tumbled quartz-rich stone, likely druzy quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Limestone

Calcium Carbonate (CaCO3)

Sand (Construction Grade)

Unconsolidated siliciclastic sediment (primarily SiO2)

Clear Quartz (Crystal Quartz)

Silicon Dioxide (SiO2)

Smoky quartz fragment

Quartz, silicon dioxide (SiO₂), smoky variety

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Tumbled rose quartz

Quartz, silicon dioxide (SiO₂), pink variety