Sedimentary (Biogenic Sediment Or Biological Remain)

Chert (and Limestone) River Cobble

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert / Flint

Chert (SiO2)

Chert (with Quartz Vein)

Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)

Chert (specifically Red Chert / Jasper)

Silicon Dioxide (SiO2)

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (variant Flint)

Silicon Dioxide (SiO2)

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

Chert Pebble

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (specifically Yellow Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Mookaite Jasper

Silicified radiolarite (SiO2)

Tufa (Vesicular Limestone)

Tufa (form of Calcium Carbonate, CaCO3)

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)

Chert (and Limestone)

Silicon Dioxide (SiO2)

Liesegang Banded Sandstone (Wonderstone)

Ferruginous Sandstone with Liesegang Rings

Northern Shoveler Duck (Note: This is a biological specimen, not a rock)

Spatula clypeata

Chert (Flint variety)

Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2

Chert (Quartz Variety)

Chert (Silicon Dioxide, SiO2)

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Yellow or Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Banded Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (River Stone/Pebble)

Chert (SiO2)

Fossiliferous Limestone (Chertified Limestone)

Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Blue Kyanite

Kyanite (Al2SiO5)

Chert / Flint

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (varieties include Jasper or Flint)

Chert (Microcrystalline Silica, formula: SiO2)

Pearl

Aragonite (CaCO3) with Conchiolin

Chert (Gravel)

Chert (Cryptocrystalline silicon dioxide, SiO2)

Chalk

Calcium Carbonate (CaCO3)

Chert (specifically Iron-stained or Jasperoid Chert)

Microcrystalline Quartz (SiO2)

Chert (often called Flint in this context)

Silicon Dioxide (SiO2)

Chert (Cherty Limestone or Flint)

Microcrystalline Silica (SiO2)