Sedimentary Rock (Metamorphosed)

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Chert (Arrowhead)

Chert (primarily Microcrystalline Silica, SiO2)

Gneiss (specifically Granitic Gneiss)

Gneissic Metamorphic Rock

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Sandstone (Quartz Sandstone)

Arenite (primarily SiO2)

Concretion

Various mineral compositions, typically carbonate or iron oxide cemented sediment

Sandstone

Arenite (SiO2 based with various mineral cements)

Gneiss

Gneiss (High-grade metamorphic rock)

Sandstone

Arenite (composed primarily of SiO2)

Quartz Vein in Sedimentary Rock

Silicon Dioxide (SiO2) with host Chert or Limestone

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with Iron Oxide cement)

Sandstone (Iron-stained)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 based)

Tiger's Iron

Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)

Dalmation Stone

Peralkaline Rock (mixed silicate minerals)

Dalmation Stone (often called Dalmatian Jasper)

Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite

Sandstone

Arenite (SiO2 primarily)

Sandstone

Arenite (SiO2 principal)

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (likely Arkose or Quartz Sandstone)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

Geode (Chert or Quartz Nodule)

Silicon Dioxide (SiO2)

Sandstone (Quartzite Pebble)

Arenite (primarily SiO2)

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Sandstone (lithic/greywacke variant)

Clastic sedimentary rock (primarily SiO2 with rock fragments)

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2)

Granular Sandstone

Arenite (variable composition, primarily SiO2)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Shale

Laminated Mudstone

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Goethite/Hematite shell with Sandstone core)

Druzy Quartz on Matrix (likely Limestone or Sandstone)

Silicon Dioxide (SiO2) with various trace impurities

Limonite stained Sandstone

Sedimentary rock with Goethite/Limonite (FeO(OH)·nH2O)

Sandstone with Quartz Veining

Clastic sedimentary rock (SiO2 dominated)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Silica (SiO2)

Sandstone (with Iron concretions/staining)

Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)

Sandstone (likely Calcareous or Micaceous)

Clastic sedimentary rock (primarily Quartz with Cementing Agents)

Sandstone or Mudstone

Sedimentary Rock (Sandstone/Mudstone)