Rock (Likely Sedimentary)

Sandstone

Arenite (primarily SiO2)

Quartz Mica Schist

Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)

Sandstone

Arenite (primarily SiO2 - Silicon Dioxide)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Chert with Desert Varnish

Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating

Banded Calcite (Green Onyx)

Calcium Carbonate (CaCO3)

Carnelian

Carnelian Chalcedony (SiO2 with iron oxide impurities)

Dyed Agate

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Dalmatian Jasper

Peralkaline rhyolite

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Sandstone (Ferruginous)

Arenite (with Iron Oxides)

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

Hag Stone (Piddock bored rock)

Calcareous sedimentary rock featuring Pholadidae borings

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Biotite Schist with Garnet

Garnet-Biotite Schist

Aventurine (likely Green Aventurine)

Aventurine (a variety of quartz, SiO₂, with common inclusions of fuchsite)

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Jasper (Yellow/Brown variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Chert (Siliceous Mudstone variant)

Microcrystalline quartz (SiO2)

Bauxite

Bauxite (Al2O3·nH2O)

Sandstone (Red Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Bauxite

Bauxite (Al2O3·2H2O)

Sandstone (Ferruginous)

Arenite (iron-rich)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Chert (Red/Brown Variety)

Microcrystalline quartz (SiO2)

Coquina

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Gneiss (with Quartzite and Biotite)

Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with Fe2O3)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)