Sedimentary (Fossilized Organic Remain)

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Pyrite Geode (Sparkling Druzy)

Iron Sulfide (FeS2) in Sedimentary Nodule

Fossiliferous Limestone (Coral Fossil)

Scleractinian Coral in Calcium Carbonate (CaCO3)

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Yellow/Brown Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline quartz (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Red Rhyolite Porphyry

Rhyolite (Porphyritic texture)

Porphyritic Basalt

Amygdaloidal Porphyritic Basalt

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Petrified Wood

Silicified Wood (primarily SiO2)

Dinosaur Fossil (Skull)

Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint or River Pebble)

Chert (Microcrystalline Quartz, SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Green variety)

Microcrystalline Opaline/Quartz (SiO2)

Chert (often called Flint in archaeological contexts)

Silicon Dioxide (SiO2)

Banded Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert (Flint Nodules)

Chert (Microcrystalline Quartz, SiO2)

Chert (Flint variety)

Microcrystalline Silica (SiO2)

Chert Pebble (Jasper/Quartz variety)

Microcrystalline Quartz (SiO2)

Chert (Green variety)

Cryptocrystalline Quartz (SiO2)

Chert (specifically a nodule with Chalcendony/Agate banding)

Microcrystalline Quartz (SiO2)

Chert (and Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White-Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Red Chert (Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Chert (Quartz Variety)

Chert (SiO2)

Chert (Gravel)

Microcrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Red Chert / Flint)

Silicon Dioxide (SiO2)

Chert (White Chert/Flint)

Chert (SiO2)

Chert (Quartz)

Microcrystalline Silica (SiO2)

Chert (varieties include Jasper or Flint)

Chert (Microcrystalline Silica, formula: SiO2)

Chert (Brecciated River Cobble)

Silicon Dioxide (SiO2)

Banded Chert (River Stone/Cobble)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Common Chert)

Silicon Dioxide (SiO2)

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)