Sedimentary (Secondary Classification: Cryptocrystalline Quartz)

Cryptocrystalline Quartz (Agate/Chert)

Silicon dioxide (SiO2)

Turquoise in Matrix

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Gossan (Iron Hat) with Quartz and Chlorite

Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite

Chert (Tan/Grey)

Chert (Silicon Dioxide, SiO2)

Chert (and Flint)

Silicon dioxide (SiO2) - Microcrystalline or Cryptocrystalline Quartz

Chert (with Epidote/Quartz veining)

Cryptocrystalline silica (SiO2) with Epidote/Quartz inclusions

Bloodstone

Heliotrope (cryptocrystalline Quartz, SiO2 with inclusions of Hematite)

Jasp-Agate

Cryptocrystalline Quartz (SiO2) with Iron Oxide inclusions

Red Chert (Jasper)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Yellow Jasper

Silicon Dioxide (SiO2) - Impure Cryptocrystalline Quartz

Chert (specifically Flint or Jasper variant)

Microcrystalline silica (SiO2)

Gold

Native Gold (Au)

Gold

Native Gold (Au)

Dendritic Agate or Spotted Quartzite

Silicon Dioxide (SiO2) with inclusions

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper

Silicon Dioxide (SiO2) with impurities

Fancy Jasper (Agate/Chert mix)

Silicon Dioxide (SiO2) with impurities

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Limestone with Calcite Crust

Sedimentary Calcium Carbonate (CaCO3)

Chert (Iron-rich)

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

Yellow Chert (Yellow Jasper)

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite inclusions

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Red Jasper

Cryptocrystalline Quartz (SiO2 with Iron oxide inclusions)

Chert (vuggy variety)

Microcrystalline silica (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Carnelian and Mixed Agates

Cryptocrystalline Quartz (SiO2 with Iron Oxide impurities)

Botryoidal Goethite

Goethite (α-Fe3+O(OH))

Limonite (Iron Ore)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Limonite (Iron Ore Congcretion)

Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

Chert (specifically Jasper/Flint)

Chert (SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz Pebble (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Chert (Microcrystalline Quartz, SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2) with Limonite/Goethite

Basalt Pebble with Quartz Veining

Basalt (extrusive volcanic rock)

Chert (Nodule)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Petrified Wood

Silicified Wood (SiO2)