Sedimentary (Primary) With Artificial Modification

Iron Ore (Hematite/Magnetite mixture)

Ferrous Oxide (Fe2O3 / Fe3O4)

Fossiliferous Limestone with Rugose Coral

Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)

Limonite with Hematite

Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Specular Hematite (Polished Sphere)

Hematite (Alpha Fe2O3)

Limonite (Iron Ore)

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

Bauxite

Bauxite (principal ore of aluminum, primarily Al(OH)3)

Hematite

Iron(III) oxide (Fe2O3)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Chert (River Stone)

Silicon Dioxide (SiO2)

Chert (Jasper)

Silicon dioxide (SiO2)

Chert (and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or cryptocrystalline quartz (SiO2)

Limonite Concretion (Ironstone)

Limonite (FeO(OH)·nH2O) with Goethite and Hematite

Chert (specifically Red Chert / Jasper)

Silicon Dioxide (SiO2)

Chert / Flint

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Chert Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Common Opal/Agate mixture)

Microcrystalline Quartz (SiO2)

Chert (often referred to as Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint or Jasper based on color)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (varieties include Jasper or Flint)

Chert (Microcrystalline Silica, formula: SiO2)

Chert (specifically Chalcedony or Flint variation)

Microcrystalline Quartz (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Chert (often called Flint)

Chert (Cryptocrystalline Silica, SiO2)

Limestone

Calcium Carbonate (CaCO3)

Limestone (specifically Dolomitic/Crystalline Limestone)

Sedimentary Carbonate Rock (CaCO3 / CaMg(CO3)2)

Limestone

Calcium Carbonate (CaCO3)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

Gold Ore

Native Gold (Au)

Sandstone (Quartz-rich)

Clastic sedimentary rock (SiO2 primary)

Limestone

Sedimentary rock composed of Calcium Carbonate (CaCO3)

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 oxides)

Chert (varietal Flint)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Ironstone with Limonite/Goethite coating

Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O)