Organic (Non Rock)

Clear Quartz

Silicon Dioxide (SiO2)

Sandstone

Arenite

Green Quartzite

Quartzite (SiO2 with chromium-rich muscovite/fuchsite inclusions)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (likely River-tumbled Picture Sandstone)

Arenite (predominantly SiO2 with iron oxide impurities)

Quartzite

Quartzite (mostly SiO2)

Quartzite Pebble

Quartzite (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Quartzite River Rock (with Quartz Vein)

Quartzite (SiO2)

Chert (with Quartz Vein)

Microcrystalline silica (SiO2)

Magnetite / Hematite mix (Iron Ore)

Fe3O4 (Magnetite) / Fe2O3 (Hematite)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (Quartzose)

Arenite (composed mainly of SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Banded Agate

Cryptocrystalline Quartz (SiO2)

Banded Chert (Agate)

Silicon Dioxide (SiO2)

Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Amethyst

Crystalline Silicon Dioxide with Iron impurities (SiO2)

Gold

Native Gold (Au)

Quartz Geode (Druzy)

Crystalline Silicon Dioxide (SiO2)

Sandstone (Greywacke)

Arenite / Clastic Sedimentary Rock

Chrysoprase (Nickel-bearing Chalcedony)

Silicon Dioxide (SiO2) with traces of Hydrous Nickel Silicates

Quartz / Quartz Geode fragment

Silicon Dioxide (SiO2)

Amethyst (Variety of Quartz)

Silicon Dioxide (SiO2) with iron impurities

Carnelian

Carnelian (SiO2)

Chert (specifically Yellow or River Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amethyst (Tumbled)

Quartz (Silicon Dioxide, SiO2) with iron impurities

Ferruginous Quartz

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Prasiolite

Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Citrine (Heat-Treated Amethyst)

Silicon Dioxide (SiO2)

Ferruginous Chert

Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)

Sandstone

Arenite (primarily SiO2)

Jasper

Silicon dioxide / Chalcedony (SiO2)

Tiger's Eye

SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)

Tiger's Eye (likely Hawk's Eye variant)

Pseudomorph of Quartz after Crocidolite (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron impurities

Carnelian

Carnelian (variety of Chalcedony, SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)