Metamorphic Rock (Variety Of Quartz)

Pyrite

Iron Sulfide (FeS2)

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Tree Agate (Dendritic Agate)

Silicon Dioxide (SiO2) with Manganese/Iron inclusions

Feldspar (specifically Orthoclase)

Potassium Aluminum Silicate (KAlSi3O8)

Aventurine (likely Green Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Blue Calcite

Calcite (CaCO3)

Quartzite Pebble

Quartzite (composed primarily of Silica, SiO2)

Quartzite

Quartzite (primarily SiO2)

Smoky Quartz with Hematite inclusions

Silicon Dioxide (SiO2) with Fe2O3 inclusions

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Smoky Quartz

Smoky Quartz (Silicon Dioxide - SiO2)

Amygdaloidal Rhyolite

Amygdaloidal Rhyolite (Felsic volcanic rock)

Druzy Quartz Geode (likely Smokey Quartz variety)

Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.

Quartzite Pebbles

Crystalline silica rock (SiO2)

Iron-stained Quartzite

Metamorphosed Quartz (SiO2) with Hematite/Limonite impurities

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3Si2O5(OH)4

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

Pseudomorph of Quartz after Crocidolite (SiO2)

Granite

Phaneritic intrusive igneous rock

Milky Quartz

Silicon Dioxide (SiO2)

Agate Geode / Thunderegg

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Quartzite with Hematite staining

Metamorphosed Quartz Sandstone (SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Blue Sapphire (Tumbled/Polished)

Corundum (Al2O3)

Quartz (Smoky/Druzy variety)

Silicon Dioxide (SiO2)

Yellow Quartzite (River Pebble)

Metamorphic Quartzite (SiO2)

Banded Gneiss

Gneiss (variable mineral composition)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartzite (Tumbled Pebble)

Metamorphosed Quartz Sandstone (SiO2)

Unakite

Epidotized Granite

Amethyst

SiO2 (Silicon Dioxide) - a variety of Quartz

Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz

Quartzite pebble

Metamorphic Quartzite (primarily SiO2)

Quartzite Pebble

Metamorphic Quartzite (SiO2)

Jasper in Quartzite (likely Cinnabar or Iron inclusions)

Silicon dioxide (SiO2) with impurities

Jasper and Agate

Microcrystalline Quartz (SiO2)

Jasper

Jasper (Silica/Quartz) - SiO2

Rhyolite

Rhyolite (felsic extrusive igneous rock)

Unakite

Epidotized Granite

Pink Granite Gneiss

Gneiss (High-grade metamorphic rock)

Chert (Flint)

Chert (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Banded Calcite (often sold as 'Mexican Onyx')

Calcite (Calcium Carbonate, CaCO3)