Mineral And Glass

Amethyst (Chevron Amethyst/Dream Amethyst)

Silicon Dioxide (SiO2) with trace Iron impurities

Strawberry Quartz (or Sunstone / Tumbled Quartz)

Silicon Dioxide (SiO2) with Hematite/Lepidocrocite inclusions

Clear Quartz

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Quartz in Matrix (possibly with Biotite or Hornblende)

Quartz (Silicon Dioxide, SiO2) in Granitic Matrix

Quartz

Silicon Dioxide (SiO2)

Green glass cabochon or tumbled stone

Indeterminate; likely man-made glass, possibly aventurine glass rather than a natural mineral

Quartz

Silicon Dioxide (SiO2)

Quartz Crystal Cluster / Quartzite

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Raw milky quartz (likely quartz/chalcedony fragment)

Quartz, silicon dioxide (SiO₂)

Libyan Desert Glass

Impact-melt silica glass (SiO2 + traces of Al, Fe, Ti)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Muscovite Mica (with Quartz)

Muscovite (KAl2(AlSi3O10)(OH)2)

Muscovite Mica

KAl2(AlSi3O10)(F,OH)2

Green Fluorite (Botryoidal/Massive)

Calcium Fluoride (CaF2)

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right)

Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)

Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Muscovite Mica

KAl2(AlSi3O10)(F,OH)2

Muscovite Mica (likely on Quartz/Feldspar)

Muscovite - KAl2(AlSi3O10)(OH)2

Rounded quartz-rich beach pebble

Likely milky quartz or quartzite (SiO₂)

Iron-stained Quartz

Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)

Goldstone

Aventurine Glass (SiO2 + Cu small inclusions)

Milky quartz-bearing rock, possibly quartzite

Quartz (SiO₂), likely in a quartzite or quartz-rich metamorphic matrix

White Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Iron-Stained)

Crystalline Silicon Dioxide (SiO2)

Red Slag Glass

Amorphous Silica (Industrial byproduct with metallic oxide dopants)

Blue glassy mineral fragment, possibly sodalite or dyed/cobalt glass

Uncertain; likely sodalite (Na₈Al₆Si₆O₂₄Cl₂) if natural, but vivid blue color may indicate cobalt-colored glass

Clear Quartz

SiO2 (Silicon Dioxide)

Clear quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Obsidian

Volcanic glass (SiO2-rich extrusive igneous rock)

Cullet (Slag Glass)

Amorphous Silica (SiO2) with various metal oxide colorants

Pegmatite (Feldspar and Quartz)

Pegmatite (KAlSi3O8 / SiO2)

Quartz

Silicon dioxide (SiO2)

Clear quartz crystal (likely vein quartz)

Quartz, silicon dioxide (SiO₂), most likely colorless macrocrystalline quartz

Sandstone

Clastic Sedimentary Rock

Tektite

Tektite (meteoritic glass)

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz