Sedimentary Rock (Possibly Conglomerate Or Breccia With A Quartz Vein)

Sandstone

Arenite (SiO2 based clastic rock)

Clear Quartz

Silicon Dioxide (SiO2)

Chert (varieties include Flint or Jasper)

Chert (cryptocrystalline quartz; SiO₂)

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Red Sandstone Pebble

Arenite (primarily Quartz SiO2 with Hematite Fe2O3 staining)

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)

Red Jasper (Plum or Brick variety)

Silicon Dioxide (SiO2) with iron oxide inclusions (Hematite)

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

Red Sandstone

Arenite (ferruginous sandstone)

River Cobble (Salt and Pepper Gneiss)

Gneiss (High-grade regional metamorphic rock)

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Turquoise

Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss

Gneiss

Mica Schist

Mica Schist (primarily Muscovite and Quartz)

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartzite Pebble (River Rock)

Metamorphic Quartzite (predominantly SiO2)

Amethyst Quartz

Silicon Dioxide (SiO2 with iron impurities)

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Chert (and Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz (Milky or Clear fragment)

Silicon Dioxide (SiO2)

Quartz (Milky/Crystalline fragment)

Silicon Dioxide (SiO2)

Rough Quartz (likely Rose or Smoky variant)

Silicon Dioxide (SiO2)

Agate (Carnelian-Blue Agate mix)

Silicon Dioxide (SiO2)

Quartz (Milky or Rough Variety)

Silicon Dioxide (SiO2)

Quartz (specifically Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Gneiss (Granitic Gneiss)

Gneiss (from German Gneis, related to 'spark')

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Chalcedony (Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Gneiss

Gneiss (High-grade Metamorphic Rock)

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2)

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

Septarian Nodule (Galt)

Calcareous concretion / Septarian concretion

Quartz (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Jasper (Red Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Pyrite in Shale

Iron Disulfide (FeS2) in Argillaceous Shale

Black River Stone (Chert or Basalt Pebble)

Microcrystalline Quartz (SiO2) or Mafic Igneous Rock

Dalmatian Stone (often called Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)