Sedimentary Or Igneous (Host Environment)

Sandstone (Ferruginous/Red Sandstone)

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Petrified Wood

Silicified Wood (SiO2)

Quartz

Silicon Dioxide (SiO2)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Concretion

Various mineral compositions, typically carbonate or iron oxide cemented sediment

Jasper

Jasper (Silica, SiO2)

Banded Flint (Polished Stripe Flint)

Silicon Dioxide (SiO2) - variety of Chert

Sandstone Pebble with Iron Staining

Clastic Sedimentary Rock (primarily Quartz with Fe2O3 oxides)

Fire Opal in Host Rock

Amorphous Hydrous Silica (SiO2·nH2O)

Quartz Vein in Host Rock (Pebble)

Quartz (SiO2) with sandstone or siltstone matrix

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Matrix

Quartz Geode (with possible Manganese or Goethite coating)

Silicon Dioxide (SiO2)

Granite Sand (Decomposed Granite)

Grus / Quartz-Feldspar Detritus

Coarse-grained Granite (Quartz and Feldspar dominated)

Granitoid (KAlSi3O8 – NaAlSi3O3 – CaAl2Si2O8 – SiO2)

Sandstone (Red Sandstone / River Stone)

Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)

Red Sandstone

Quartz Arenite (with Iron Oxide)

Red Sandstone

Arenite (primarily composed of SiO2 with Fe2O3 cement)

Granitic Pegmatite Intrusion in Host Rock

Pegmatite dike in amphibolite or schist

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Quartz (Milky/Gray variety)

Silicon Dioxide (SiO2)

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / River Pebble

Microcrystalline Silica (SiO2)

Fossiliferous Limestone (Chert/Clay mixed)

Calcium Carbonate (CaCO3) / Silicon Dioxide (SiO2)

Petrified Wood (Agatized/Silicified Wood)

Silicified Paleoxylon (primarily SiO2)

Red Sandstone

Arenite (Fe2O3-rich)

Fluorite

Calcium Fluoride (CaF2)

Garnet (Almandine or Spessartine likely)

Garnet Group Minerals (e.g., Almandine Fe3Al2(SiO4)3, Pyrope Mg3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Green Tourmaline (Verdelite)

Tourmaline Group; often Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4) or Dravite (NaMg3Al6(BO3)3Si6O18(OH)4)

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone Cobble

Arenite (Secondary classification based on grain size)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Copper and Quartz beads

Native Copper (Cu) and Crystalline Quartz (SiO2)

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Orange Calcite

Calcite (CaCO3)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)