Sedimentary Rock (Cryptocrystalline Quartz)

Quartzite Cobble

Quartzite (composed primarily of SiO2)

Clear Quartz (Druzy)

Crystalline Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (SiO2 matrix with various silicate clasts)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Arkosic Sandstone

Arkose

Sandstone

Arenite (SiO2-rich)

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Chert (Septarian Nodules / Weathered Silex)

Microcrystalline Quartz (SiO2)

Shiva Lingam

Cryptocrystalline Quartz (Jasperiod Silicate with Iron Oxide inclusions)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Dalmatian Stone

Peralkaline Feldsphathic Igneous Rock

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone

Arenite (primarily Quartz Sandstone with Iron Oxide)

Quartz

Quartz (SiO₂)

Quartz (Milky or Common Quartz)

Silicon Dioxide (SiO2)

Limonite-stained Chert/Jasper

Microcrystalline Quartz (SiO2) with Iron Oxides (FeO(OH)·nH2O)

Red Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

White Quartz

Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Riverstone (Quartzite or Siltstone cobble)

Quartzite (primarily SiO2)

Sandstone

Arenite

Sandstone

Clastic Sedimentary Rock (composed primarily of Quartz, SiO2)

Conglomerate (Red Sandstone variety)

Clastic Sedimentary Rock (Conglomeratic Sandstone)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2 with minor Fe2O3)

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Sandstone

Arenite or Sandstone

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling

Sandstone

Arenite (SiO2 principal component)

Mookaite Jasper

Silicified Radiolarite (SiO2)

Onyx

Chalcedony (SiO2) with parallel banding

Chert (Hagstone/Gasket Rock variant)

Chert (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)