Organic Gemstone (Sedimentary Classification)

Chert (Flint)

Chert (SiO2)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone (Concretionary or Tufa)

Calcium Carbonate (CaCO3)

Fossilized Shark Tooth (Basal Bone)

Otodus sp. (Mineralized Hydroxyapatite)

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossilized Pycnodonte Oyster

Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)

Shale (with minor calcite veining)

Clastic sedimentary rock (primarily clay minerals and quartz)

Chert (and Jasper blend)

Chert (Microcrystalline Quartz, SiO2)

Chert (with Limestone/Dolomite host)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (Pink Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossilized Shark Tooth

Scapanorhynchus (Sand Tiger Shark relative)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Chert Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fossilized Dinosaur Skull (Tyrannosaurus rex)

Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

Fossil Shark Tooth

Carcharodon or Carcharias fossil (Vertebrate Fossil)

Chert (with Quartz Veining)

Microcrystalline silicon dioxide (SiO2)

Chert (often referred to as Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Chert (Jasper/Quartzite river stone)

Microcrystalline Silicon Dioxide (SiO2)

Glauconitic Sandstone

Glauconitic Quartz Arenite

Chert

Chert (SiO2)

Chert (Tan/Grey)

Chert (Silicon Dioxide, SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (variations include Flint/Jasper)

Chert (SiO2)

Chert (Fossiliferous)

Silicon Dioxide (SiO2)

Chert (Quartz Variety)

Chert (SiO2)

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)