Sedimentary (Physico Chemical Precipitate)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Quartz (Raw Chunk)

Silicon Dioxide (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Chert (with Manganese Dendrites)

Chert (Cryptocrystalline Quartz, SiO2)

Quartz Geode (Cracked Open Fragment)

Silicon Dioxide (SiO2)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Chert

Microcrystalline silica (SiO2)

Banded Iron Formation (BIF) with Quartz

Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Banded Onyx (Cave Calcite)

Calcite (CaCO3), often called Mexican Onyx or Travertine

Chert (with Quartz vein/coating)

Microcrystalline Quartz (SiO2)

Yellow Jasper / Chert

Silicon Dioxide (SiO2) with Goethite or Limonite inclusions

Banded Iron Formation (BIF)

Magnetite-hematite-chert formation

Chert (Light Grey / Flint variant)

Cryptocrystalline Quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

Yellow Chalcedony (Agate/Chert)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Ironstone Concretion (Limonite/Goethite)

Goethite-rich Concretion (FeO(OH))

Agate

Chalcedony (Silicon Dioxide, SiO2)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Crystalline Quartz (Rough)

Quartz (Silicon Dioxide, SiO2)

Sandstone (with Liesegang rings or Oxidation)

Arenite (primarily Quartz SiO2 with Iron Oxide Fe2O3 staining)

Orange Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Septarian Nodule

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

Quartz (Milky/Bull Quartz)

Silicon Dioxide (SiO2)

Banded Onyx (Green Onyx)

Banded Calcite or Travertine (CaCO3)

Tufa

Calcareous Tufa (Calcium Carbonate, CaCO3)

Turquoise

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

Milky or Iron-Stained Quartz

Quartz (Silicon Dioxide, SiO2)

Aragonite (Onyx Marble)

Calcium Carbonate (CaCO3), Orthorhombic crystal system

Barite Rose on Marcasite

Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)

Agate

Agate (Silicon Dioxide - SiO2)

Coquina Limestone (Fossiliferous Limestone)

Calcareous bioclastic sedimentary rock (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Honey Calcite

Calcium Carbonate (CaCO3)

Geode (unopened) or Calcareous Nodule

Siliceous or Calcareous Concretion/Nodule

Celestite (Celestine)

Strontium Sulfate (SrSO4)

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Banded Sandstone (Liesegang Rings)

Sedimentary Arenite (SiO2 with FeO/Fe2O3 impurities)