Sedimentary (Chemically Precipitated Mineral)

Chert (Cherty Flint/Jasper variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Banded Calcite (often sold as 'Ocean Jasper' or 'Caribbean Calcite' variant)

Calcium Carbonate (CaCO3) with potential Aragonite inclusions

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Chert Pebble Map

Microcrystalline Quartz (SiO2)

Banded Chert (River Stone/Cobble)

Microcrystalline Quartz (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Milky/Common variant)

Silicon Dioxide (SiO2)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Ferruginous Sandstone (Gozzan/Ironstone)

Arenite with Limonite/Goethite cement (FeO(OH)·nH2O)

Orange Calcite

Calcium Carbonate (CaCO3)

Septarian Nodule (Dragon Stone)

Septarian concretion (composition: Calcium Carbonate / Calcite, Aragonite, and Limestone/Clay)

Quartz

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Quartz Geode

Crystalline Quartz (Silicon Dioxide, SiO2)

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Chert (vuggy/nodular)

Microcrystalline Quartz (SiO2)

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

Bauxite

Bauxite (mixture of Hydrous Aluminum Oxides)

Bauxite

Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))

Chert / Flint Conglomerate

Silicified Sedimentary Breccia (primarily SiO2)

Blue Apatite

Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)

Limestone

Calcium Carbonate (CaCO3)

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Bauxite

Bauxite (Al2O3·nH2O)

African Turquoise

African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Septarian Nodule (or Mudstone with Septarian Cracking)

Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Claystone)

Moqui Marble

Iron Oxide Concretion (Limonite/Hematite over Sandstone)

Jasper

Jasper (Silicon Dioxide, SiO2)

Limestone

Calcium Carbonate (CaCO3)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)