Organic (Sedimentary Context)

Chert (often called Flint in this context)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Goethite pseudomorph after Pyrite

Goethite (FeO(OH)) pseudomorph after Pyrite (FeS2)

Chert (often called Flint in this context)

Silicon Dioxide (SiO2)

Chert / Flint Arrowheads

Cryptocrystalline Quartz (SiO2)

Fossil bivalve shell

Fossilized or partially mineralized bivalve; exact genus cannot be determined from the image

Hag Stone

Perforated Sedimentary Rock (typically Sandstone or Siltstone)

Sandstone (Water-worn Cobble)

Arenite (variable composition, primarily SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Red Jasper

Silicon Dioxide (SiO2) with Iron inclusions

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Hematite (Tumbled)

Iron(III) oxide (Fe2O3)

Orange Calcite

Calcium Carbonate (CaCO3)

Ferruginous Sandstone

Ferruginous Sandstone (Quartz Arenite with Iron Oxide cement)

Asphalt (Bituminous Pavement Bit)

Bitumen-bound aggregate (Petrochemical-bound composite)

Unidentified Rock Fragment

Unknown

Chert (specifically Flint or Dark Chert)

Silicon Dioxide (SiO2)

Chert (Cream Variety)

Microcrystalline silica (SiO2)

Red Sandstone

Arenite (primarily SiO2 with Fe2O3)

Bivalve Fossil (Clam)

Class Bivalvia (e.g., Mercenaria or similar genus), composed of CaCO3 (Aragonite/Calcite)

Jasper Marble

Silicon Dioxide (SiO2) with Impurities

Black Jasper

Silicon dioxide (SiO2) with carbon/mineral inclusions

Ironstone Concretion (Moqui Marble type)

Ironstone Concretion (Fe2O3 with SiO2 core)

Fossiliferous Limestone with Crinoid Stem fragment

Calcite (CaCO3) containing Crinoidea fossils

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Baroque Pearl

Calcium Carbonate (Aragonite or Calcite) and Conchiolin

Wishing Rock (Quartz Vein in Host Rock)

Silicon dioxide (SiO2) vein in various host rocks

Red Sandstone

Arenite (Ferruginous Sandstone)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Rounded gray stone, likely quartz-rich granitic rock

Probable granite or granitic gneiss; mainly quartz, feldspar, and mica

Yellow Jasper

Silicon Dioxide (SiO2)

Milky Quartz Pebble with Iron Inclusions

Silicon Dioxide (SiO2) with iron oxide impurities

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) in Carbonate Matrix

Sea Shell (Fighting Conch Fragment)

Calcium Carbonate (CaCO3) - Strombus alatus fragment

Weathered sandstone or iron-rich sedimentary fragment

Quartz-rich sandstone, possibly ferruginous sandstone (SiO₂-dominant)

Chert (often called Flint in archaeological contexts)

Silicon Dioxide (SiO2)

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Leopard Skin Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Ferruginous Sandstone (Gritstone)

Clastic sedimentary rock with iron-rich cement (FeO(OH)·nH2O)

Potassium-Rich Silicate Clay (inferred from biological context)

Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)

Ironstone Concretion (Moqui Marble)

Iron-oxide concretion (Fe2O3 / FeO(OH))

Chert (Nodule)

Cryptocrystalline Silica (SiO2)

Ferruginous Sandstone (Ironstone Conglomerate fragments)

Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)