Sedimentary Rock (Cryptocrystalline Quartz)

Sandstone

Arenite (SiO2 based with mineral cement)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Quartz Variety)

Microcrystalline Silica (SiO2)

River Quartzite Siltstone

Quartz-rich Meta-siltstone (SiO2 dominated)

Iron-stained Quartzite / Chert

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Red Sandstone

Arenite (primarily Quartz with Iron Oxide coating)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Chert (Jasper/Jasperoid)

Chert (chemically precipitated microcrystalline Quartz, SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) within a nodule

Orbicular Rhyolite (Rainforest Jasper)

Rhyolite containing Spherulites (SiO2 with impurities)

Ocherous Sandstone (Ferruginous Sandstone)

Ferruginous Arenite (SiO2 with Fe2O3)

Weathered Quartzite or Chert Pebble

Silicon Dioxide (SiO2)

Sandstone (Quartz-rich Pebble)

Arenite (primarily SiO2)

Sandstone (Quartz Sandstone)

Clastic sedimentary rock (primarily SiO2)

Red Jasper

Jasper (Silicon Dioxide: SiO2 with Iron oxide inclusions)

Conglomerate

Conglomerate Rock (Paraconglomerate)

Quartz Geode/Cluster

Quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Blue Chalcedony

Microcrystalline Quartz (SiO2)

Turquoise

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

Sandstone with Tafoni Weathering

Arenite (SiO2 based)

Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')

Calcium Carbonate (CaCO3)

Sandstone (Red)

Arenite (SiO2 with Fe2O3)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Sandstone

Arenite (SiO2 + various cementing minerals)

Quartz Geode (Smoky Quartz)

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (High-grade metamorphic rock)

Quartz Geode

Silicon Dioxide (SiO2)

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz with Fe2O3 staining)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Quartz-veined Schist (or Metasandstone)

Metamorphic Rock with Quartz Veining (SiO2)

Micro-crystalline Quartz Pebble (Chert)

Silicon dioxide (SiO2)

Carnelian

Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)

Gneiss with Quartz/Feldspar Vein

Quartz-Feldspathic Gneiss

Sandstone (Ferruginous)

Arenite (with Iron Oxides)

Jasper

Silicon dioxide (SiO2) with impurities