Organic (Zoogenic)

Chert (and associated Sedimentary rocks)

Microcrystalline Silica (SiO2)

Mica Schist

Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)

Chert

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Granite

Granite (Phaneritic Igneous Rock)

Quartzite

Quartzite (primarily SiO2)

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Mookaite Jasper

Mookaite (variety of Chert/Jasper), Silicon Dioxide - SiO2

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite

Quartzite (SiO2)

Chert (often called Flint when dark)

Microcrystalline silicon dioxide (SiO2)

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Garnet Schist

Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)

Chert (Flint variety)

Silicon Dioxide (SiO2)

Banded Chert

Cryptocrystalline Quartz (SiO2)

Banded Chert (River Cobble)

Microcrystalline Quartz (SiO2)

Greenstone

Chlorite schist / Meta-basalt

Quartzite

Quartzite (primarily SiO2)

Banded Iron Formation (Jaspilite)

Banded Iron Formation (BIF); predominantly Hematite (Fe2O3) and Magnetite (Fe3O4) with Chert/Jasper (SiO2)

Chert Pebble

Microcrystalline silica (SiO2)

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Chert (variations include Flint or Jasper)

Chert (Silicon Dioxide, SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (Yellow or Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Unakite

Unakite (Metasomatized Granite)

Chert (Arrowhead/Tool Grade)

Microcrystalline Quartz (SiO2)

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Granite (Pink/Red Orthoclase variety)

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

Quartzite

Quartzite (chiefly SiO2)

Coquina or Fossilized Shell Fragment

Calcium Carbonate (CaCO3) / Biogenic Limestone

Granite

Phaneritic Felsic Igneous Rock

Chert (Flint)

Chert (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (mostly SiO2)

Quartz vein in metamorphic rock

Crystalline Silicon Dioxide (SiO2) in Host Rock

Polished Chert (Flint)

Silicon Dioxide (SiO2)

Limestone with Calcite Veining

Calcium Carbonate (CaCO3)