Sedimentary (Secondary Formation)

Quartz (various varieties)

SiO₂ (Silicon Dioxide)

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Chert (often called Jasper or River Siltstone)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper/Carnelian variety)

Microcrystalline quartz (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Petrified Wood

Silicified Wood (primarily SiO2)

Quartz

Silicon Dioxide (SiO2)

Magnetite Orthorthotropic Rock

Magnetite (Fe3O4)

Banded Iron Formation (BIF) / Tiger Iron

Banded Iron Formation containing Hematite (Fe2O3) and Magnetite (Fe3O4)

Chert (Jasper or Flint variant)

Chert (composed of microcrystalline quartz, SiO2)

Crushed Limestone

Calcium Carbonate (CaCO3)

Sandstone (with Iron Oxide staining)

Arenite (primarily SiO2 with Fe2O3 staining)

Geode with Quartz and possibly Jasper/Hematite

Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides

Druzy Quartz on Chert/Siltstone

Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix

Chert (variously known as Flint or Microcrystalline Quartz)

Silicon dioxide (SiO2)

Red Jasper

Silicon Dioxide with Iron Oxide (SiO2)

Red Jasper (possibly Brecciated)

Jasper (Silicon Dioxide, SiO2)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Chert

Chert (microcrystalline quartz)

River Pebble Gravel

Hydrothermally modified Clastic Sediment (mainly Quartzite and Chert)

River Pebble (Quartz-rich)

Silicon Dioxide (SiO2) with various inclusions

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Chert (White Flint)

Silicon Dioxide (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Hematite (Botryoidal/Kidney Ore)

Iron(III) oxide (Fe2O3)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Chalcedony (Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Red Jasper (Brecchiated Jasper)

Silicon Dioxide (SiO2) with Hematite impurities

Hematite

Iron(III) oxide (Fe2O3)

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Chert (Field Stone)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Ironstone Concretion (Limonite/Goethite)

Iron oxide concretion (contains FeO(OH)·nH2O)

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (specifically Zebra Chert/Flint)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 principal)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Graphite-veined Quartzite

Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)