Crystal

Quartz (Crystal/Druzy Quartz)

Quartz (SiO₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Obsidian

Volcanic Glass (comprised primarily of SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Agate

SiO2

Amethyst (Polished Point)

Crystalline Quartz (SiO2 with iron impurities)

Citrine

Silicon Dioxide (SiO2)

Crazy Lace Agate

Chalcedony (SiO2)

Porphyritic Basalt (with Augite Crystals)

Porphyritic Mafic Volcanic Rock (Fe-Mg Silicates)

Citrine Quartz Crystal Cluster

Silicon Dioxide (SiO2) with iron impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Herkimer Diamond (Quartz Crystal)

Silicon Dioxide (SiO2)

Rough Rose Quartz

Quartz (Silica - SiO2)

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Potassium Feldspar, and Mica)

Snowflake Obsidian

Volcanic Glass (SiO2 + impurities)

Granitic Pegmatite

Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8, Mica: KAl2(AlSi3O10)(OH)2)

Selenite Gypsum

Hydrous calcium sulfate (CaSO4·2H2O)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (SiO₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Tumbled Amethyst and Smoky Quartz

Silicon Dioxide (SiO2) with impurities

Quartz Geode (Smoky Quartz)

Silicon Dioxide (SiO2)

Snowflake Obsidian

Vitreous volcanic rock with Cristobalite inclusions (mostly SiO2)

Dalmatian Stone

Peralkaline rhyolite with arfvedsonite (formerly incorrectly called Dalmatian Jasper)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Quartz Geode with Calcite

Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)

Angel Aura Quartz (Treated Clear Quartz)

Silicon Dioxide (SiO2) coated with Vaporized Silver and Platinum

Quartz Geode

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)