Organic (Biological Specimen)

Chert (Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and Limestone) River Cobble

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert (often called Flint or River Stone)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Chert (River Cobble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (specifically Gray/Tan Chert Node)

Microcrystalline Quartz (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert Pebble

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Green Moss Agate / Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz with Iron and Manganese inclusions

Jasper

Silicon dioxide (SiO2)

Chert (and Flint variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Dendritic Agate

Chalcedony (SiO2) with manganese/iron oxide inclusions

Chert (specifically Iron-stained or Jasperoid Chert)

Microcrystalline Quartz (SiO2)

Jasper

Jasper (Silicon Dioxide) - SiO2

Chert (Polished River Pebble)

Chert (SiO2)

Chert (Banded Variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Crinoid Fossil in Limestone

Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (concretionary/nodular variant)

Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions

Fancy Jasper (Agate/Chert mix)

Silicon Dioxide (SiO2) with impurities

Banded Chert with Quartz Veining

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone

Fossiliferous Calclutite / Bio-calcarenite (CaCO3)

Agatized Fossil or Chalcedony Nodule

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossilized Crinoid Stem

Class Crinoidea (Echinodermata)

Chert (Chalcedony/Jasper)

Microcrystalline Quartz (SiO2)

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxide

Petoskey Stone

Hexagonaria percarinata (Fossilized Coral)

Pyrite in Shale

Iron Sulfide (FeS2) in Sedimentary Matrix

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Chert (and Flint)

Silicon Dioxide (SiO2)

Fossiliferous Limestone (Crinoidal)

Calcium Carbonate (CaCO3) - Limestone containing bioclasts

Chert (White Chert)

Microcrystalline Quartz (SiO2)

Moss Agate

Chalcedony (Silicon Dioxide - SiO2) with inclusions

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)