Sedimentary Or Igneous (Secondary Formation)

Iridescent Ammonite Fossil

Ammonoidea (subclass); Composition: Aragonite (Calcium Carbonate, CaCO3) often replaced by Calcite or Pyrite

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

Picture Jasper

Silicon Dioxide (SiO2)

Red Sandstone

Arenite

Basalt with Quartz Vein

Basalt (SiO2 vein inclusion)

Jasper (Sedimentary variety)

Silicon Dioxide (SiO2) with impurities

Blue Banded Agate (Dyed)

Silicon Dioxide (SiO2) - variety of Chalcedony

Turquoise

Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)

Turquoise

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

Carnelian (Agate)

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Chalk

Calcium Carbonate (CaCO3)

Yellow Jasper (Chalcedony)

Silicon Dioxide with Iron inclusions (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Turquoise

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

Blue Celestite (with Galena)

Strontium sulfate (SrSO4) and Lead sulfide (PbS)

Agate

Silicon Dioxide / Cryptocrystalline Quartz (SiO2)

Agate (specifically Lace Agate or Banded Agate)

Silicon Dioxide (SiO2)

Jasper with Quartz Veining

Silicon Dioxide (SiO2) with impurities

Sandstone with Manganese Dendrites/Oxide coatings

Arenite with Pyrolusite and Romanechite (MnO2)

Iron Ore (Hematite/Magnetite mixture)

Ferrous Oxide (Fe2O3 / Fe3O4)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Red Jasper

Chalcedony (SiO2 with iron oxide impurities)

Puddingstone (Gowganda)

Jasper-clast Polymictic Conglomerate (Gowganda Formation)

Banded Iron Formation (BIF)

Magnetite-Hematite Chert (Banded Iron Formation)

Red Sandstone

Arenite (with Iron Oxide pigmentation)

Chert (Nodular or Fossiliferous)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Chert (specifically Agate/Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Septarian or Nodular variety)

Microcrystalline Quartz (SiO2)

Geode (Quartz)

Silicon Dioxide (SiO2)

André's Landing Rock (Sandstone Boulder)

Newark Supergroup Sandstone (likely Stockton Formation)

Banded Iron Formation (BIF) / Jasper

Banded Iron Formation (SiO2 with Fe2O3 and Fe3O4)

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Banded Iron Formation (BIF)

Banded Iron Formation (SiO2 + Fe2O3/Fe3O4)

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Basalt

Basalt (extrusive igneous rock)

Sandstone

Arenite (composed primarily of SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite impurities

Red Jasper

Quartz (Silicon Dioxide) with Iron Oxide impurities (Fe2O3)