Sedimentary (Primary) With Artificial Modification

Puddingstone

Polymictic Conglomerate

Limestone (River or Sea Cobble)

Calcium Carbonate (CaCO3)

Bauxite

Bauxite (Al(OH)3, AlO(OH))

Echinoid Fossil (Commonly called a Sea Urchin or Heart Urchin)

Phylum Echinodermata, Class Echinoidea

Fossilized Bone Fragment

Permineralized Skeletal Element (Likely Vertebrate)

Anthracite Coal

Anthracite (Metamorphosed Coal)

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Chert (Flint/Chalcedony)

Microcrystalline Quartz (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Chert (Common Variety, Jasper)

Microcrystalline Quartz (SiO2)

Chert (variant Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Chert (Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Chert / Flint Nodules in Sandstone

Microcrystalline Quartz (SiO2) within Clastic Sedimentary Rock

Red Sandstone (Old Red Sandstone)

Ferruginous Sandstone (SiO2 + Fe2O3)

Chert (Quartz)

Microcrystalline Silica (SiO2)

Chert (Nodule)

Chert (Alpha-Quartz, SiO2)

Chert (Agate/Flint variant)

Microcrystalline Quartz (SiO2)

Chert (Pink variety/Jasper)

Silicon Dioxide (SiO2)

Chert (Pink/Red variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint

Silicon Dioxide (SiO₂)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Galena

Lead(II) sulfide (PbS)

Blue Calcite

Calcium Carbonate (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Dark Chalcedony)

Silicon Dioxide (SiO2)

Chert (Jasper variety)

Microcrystalline quartz (SiO2)

Yellow Chert (River Stone)

Microcrystalline Quartz (SiO2)

Chert (Field Pebble)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Chert (varietal Flint)

Silicon Dioxide (SiO2)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Laterite (Iron-rich bauxite or Gossan)

Ferricrete (Fe2O3·nH2O)

Chert / Flint

Microcrystalline Silica (SiO2)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Blue Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Quartzite river stone)

Microcrystalline Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper depending on color)

Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)