Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Arrowhead/Tool variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (including Flint and Jasper variants)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint)

Microcrystalline to cryptocrystalline quartz (SiO2)

Chert (specifically Jasper/Brown Chert)

Silicon Dioxide (SiO2)

Red Jasper (Chert)

Silicon Dioxide (SiO2)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Chert (specifically Jasper)

Silicon dioxide (SiO2) with iron oxide inclusions

Chert (Brown variety)

Silicon Dioxide (SiO2)

Chert (specifically a Worked Flint/Knapped Flake)

Chert / Flint (Microcrystalline Quartz, SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Yellow Chalcedony

Silicon Dioxide (SiO2)

Chert (Cherty Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Quartzite variety)

Microcrystalline Silica (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (Banded Variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

Chert (specifically Flint or Jasper variant)

Cryptocrystalline Quartz (SiO2)

Banded Chert

Cryptocrystalline Quartz (SiO2)

Chert (Quartzite-rich River Pebble)

Silicon Dioxide (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert / Flint Conglomerate

Silicified Sedimentary Breccia (primarily SiO2)

Amethyst or Smoky Quartz Geode Slice

Crystalline Silicon Dioxide (SiO2) with iron impurities

Chert (specifically Blue or Grey Chert/Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Iron-stained)

Chert (primarily Microcrystalline Quartz, SiO2)

Chert (Common Opal/Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (with Quartz Veining)

Chert (formula: SiO2)

Chert (specifically Black Chert or Flint)

Cryptocrystalline Quartz (SiO2)