Sedimentary (Chemically Precipitated Mineral)

Brecciated Chert

Sedimentary Chert (SiO2) with Calc-Silicate mineralization

Green Calcite

Calcium Carbonate (CaCO3)

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Coquina

Biogenic Limestone (Calcium Carbonate - CaCO3)

Quartz (Crystal Fragment)

Silicon Dioxide (SiO2)

Almandine Garnet

Almandine, Fe3Al2(SiO4)3

Chert (specifically Green Chert/Jasper)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (containing Iron Oxide)

Microcrystalline Quartz (SiO2)

Chert (Flint variety)

Chert (SiO2)

Chert (variously identified as Flint)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite with Sandstone/Iron staining

Metamorphic Quartzite (SiO2)

Obsidian

Obsidian (Volcanic Glass, SiO2)

Chert (Black Chert/Flint)

Chert (Silicon Dioxide, SiO2)

Quartz (Water-worn pebble)

Silicon Dioxide (SiO2)

Mother of Pearl (Nacre)

Aragonite (layered with organic polymers), CaCO3

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

Halite

Halite (Sodium Chloride, NaCl)

Chert (often called Flint)

Silicon Dioxide (SiO2)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Chert (Honey Chert or Chalcedony Pebble)

Cryptocrystalline Quartz (SiO2)

Auriferous Quartz (Gold-bearing Quartz)

Silicon Dioxide (SiO2) with Elemental Gold (Au)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper)

Microcrystalline Silica (SiO2)

Quartz (Gravel fragment)

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Pink Dyed Agate

Silicon Dioxide (SiO2) with synthetic pigment

Chert (White Chert/Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Chert (and Chert-based Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)

Chert (White/Light Tan)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sulfur (with possible Cullet Glass or Slag imitation)

Native Sulfur (S8)

Chalcedony (Agate/Quartz variety)

Cryptocrystalline Quartz (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Bauxite

Bauxite (Principal ore of aluminum; mixture of minerals including Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

Banded Iron Formation (BIF)

Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])

Ironstone (likely Limonite or Goethite)

Ferruginous sedimentary rock (FeO(OH)·nH2O)

Purple Agate (Dyed Chalcedony)

SiO2 (Silicon Dioxide) with organic dyes