Sedimentary (Cryptocrystalline Quartz)

Chert (Quartz Variety)

Chert (SiO2)

Sandstone (Graywacke)

Clastic Sedimentary Rock (Lithic Sandstone)

Quartz Druzy on Geode Fragment

Silicon Dioxide (SiO2)

Gneiss

Gneiss (Metamorphic rock)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Jasper (Red and Yellow)

Silicon Dioxide (SiO2) with iron oxide impurities

Jasper (Red/Brown Variety)

Jasper (Silicon Dioxide, SiO2 plus Iron Oxide impurities)

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 impurities)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Quartz Arenite)

Sandstone (Chemical formula: primarily SiO2)

Sandstone (Weathered)

Arenite (primarily SiO2)

Red Sandstone

Arenite with Hematite (Fe2O3) cement

Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (primarily SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Quartz Geode

Quartz (Silicon Dioxide, SiO2) Geode

Quartz Geode

Silicon Dioxide (SiO2)

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Sandstone with Algae Growth

Arenite with Chlorophyta/Lichen

Sandstone Concretion with Fossil Wood

Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)

Quartzite with inclusions

Quartzite (primarily SiO2)

Feldspar

KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8

Sandstone (Quartzose)

Arenite (SiO2 based)

Gneiss (Banded Gneiss)

Gneiss

Druzy Quartz on Chert/Siltstone

Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix

Quartz (Milky or Citrine-tinted)

Silicon Dioxide (SiO2)

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

Chert Breccia

Brecciated Microcrystalline Quartz (SiO2)

Sandstone

Arenite

Yellow Quartzite (River Stone)

Quartzite (primarily SiO2)