Sedimentary

Bumblebee Jasper

Calcite with Arsenic and Manganese oxides (technically a volcanic rock)

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Calcite (Iceland Spar)

Calcite (Calcium Carbonate, CaCO3)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chalcedony (Common Opal variant or Quartz)

Silicon Dioxide (SiO2)

Sandstone

Arenite (primarily SiO2)

Geode with Quartz and Chalcedony

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Yellow/Tan)

Clastic sedimentary rock (primarily SiO2 with iron oxide staining)

Chert

Chert (Microcrystalline Silica, SiO2)

Limonitic Sandstone with Inclusion

Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)

Limestone

Calcium Carbonate (primarily CaCO3 as Calcite or Aragonite)

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)

Limestone

Calcium Carbonate (CaCO3)

Fossiliferous Chert (with Brachiopod or Mollusk fragments)

Silicon dioxide (SiO2) with Calcium Carbonate (CaCO3) inclusions

Sandstone (likely Fossilized Wood or Concrete Simulacrum)

Arenite / Silicified Wood / Anthropogenic Concrete

Chert (Brecciated Chert)

Silicon Dioxide (SiO2)

Limestone with Calcite Crystals

Calcium Carbonate (CaCO3)

Limonite and Goethite encrusted Chert/Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)

Jasper (likely Brown or Brecciated)

Jasper (Silicon Dioxide, SiO2)

Bituminous Coal

Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)

Red Sandstone

Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)

Ferruginous Sandstone (Ironstone)

Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)

Red Sandstone (Iron-rich Sandstone)

Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement

Ferruginous Sandstone

Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)

Sandstone (specifically Cross-bedded Sandstone)

Arenite (composed primarily of SiO2)

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint Nodules)

Chert (Microcrystalline Quartz, SiO2)

Gypsum (Wallboard/Drywall)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Ferruginous Sandstone (Iron-rich Sandstone)

Ferruginous Arenite

Yellow Jasper

Silicon Dioxide (SiO2)

Chert (Banded Variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gastropod Fossil (Snail Internal Mold)

Gastropoda; internal mold (steinkern), often composed of Calcium Carbonate (CaCO3) or Silica (SiO2)

Belemnite (Fossilized Rostrum)

Belemnitida (Order), composed of Calcite (CaCO3)

Ammonite Fossil (Polished Half)

Ammonoidea (subclass)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Grey-Green Flint)

Microcrystalline silicon dioxide (SiO2)

Limonite (Ironstone Concretion)

Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)

Chert (Nodule)

Cryptocrystalline Silica (SiO2)