Organic Gem Material (Botanical)

Sandy Ironstone

Ferruginous Sandstone

Yellow Quartzite Pebble

Quartzite (SiO2)

Quartzite River Rock (with Quartz Vein)

Quartzite (SiO2)

Chert (with Limonite staining)

Microcrystalline Quartz (SiO2)

Dinosaur Fossil (Skull)

Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)

Chert (specifically Brown Chert or Flint)

Cryptocrystalline Quartz (SiO2)

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Chert (Iron-stained)

Microcrystalline silica (SiO2) with trace Iron oxide (Fe2O3)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (Nodular Chert)

Silicon Dioxide (SiO2)

Pyrite in Limestone

Iron Sulfide (FeS2) in Calcium Carbonate (CaCO3)

Chert (and Limestone)

Chert (consisting of Microcrystalline Quartz, SiO2)

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Chert (Arrowhead variety)

Chert (SiO2)

Chert (Chert Nodule with Cortex)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or cryptocrystalline quartz (SiO2)

Glauconitic Sandstone (Greenstone)

Glauconitic Siliciclastic Sandstone (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

Chert (specifically Pink Chert or Jasperized Chert)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Pyrite

Iron Sulfide (FeS2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Chert (Yellow or Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (and Flint variant)

Chert (SiO2)

Yellow Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (SiO2)

Chert (Iron-rich variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert Nodule (Flint)

Microcrystalline Quartz (SiO2)

Chert (Green variety)

Chert (Silicon Dioxide, SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Geode (Unopened)

Silica-rich concretion (SiO2)

Chert (Nodule)

Chert (SiO2)

Yellow Chert (Microcrystalline Quartz)

Chert / SiO2 (Silicon Dioxide)

Chert (Flint nodule)

Silicon dioxide (SiO2)

Chert (often called Flint or River Stone)

Chert (SiO2)

Black Jasper

Silicon Dioxide (SiO2) with inclusions

Fossiliferous Limestone (Coquina / Shell Limestone)

Bioclastic Limestone (CaCO3)

Chert (and/or River Pebble)

Microcrystalline silica (SiO2)

Pyrite in Shaly Matrix

Iron Sulfide (FeS2)

Fossilized Shark Tooth (Fragment)

Elasmobranchii fossil (likely Cretalamna or Squalicorax genus)