Sedimentary (Fossil)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (likely Calcareous or Micaceous)

Clastic sedimentary rock (primarily Quartz with Cementing Agents)

Glauconitic Sandstone (Greensand pebble)

Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)

Siltstone

Siltstone (primarily composed of SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Fossilized Shark Tooth

Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron

Sandstone

Clastic sedimentary rock (primarily SiO2)

River Pebbles (Sandstone and Quartzite)

SiO2 (Quartz) dominated clastic rocks

Bituminous Coal

Bituminous coal (Organic Sedimentary Rock)

Sandstone Pebble

Arenite (primarily SiO2)

Chert (variously known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ferruginous Sandstone (Gritstone)

Clastic sedimentary rock with iron-rich cement (FeO(OH)·nH2O)

Chert / Flint

Microcrystalline Silica (SiO2)

Ironstone (Limonitic Sandstone)

Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)

Fossilized Crinoid Stem

Class Crinoidea (Echinodermata)

Chert (also known as Flint or Common Chalcedony)

Cryptocrystalline Silica (SiO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (clastic)

Clastic Sedimentary Rock (primarily composed of SiO2)

Sandstone (with potential mineral inclusions)

Clastic sedimentary rock (primarily Quartz, SiO2)

Porous Quartzite

Metamorphosed Quartz-rich Sandstone (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Limestone

Limestone (Calcium Carbonate - CaCO3)

Limestone

Calcium Carbonate (CaCO3)

River Cobble (Conglomerate context)

Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)

Sandstone (with cross-bedding)

Arenite (composed primarily of Quartz: SiO2)

Siltstone

Siltstone (composed of microscopic silt-sized particles of quartz and feldspar)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Ironstone Concretion (Ironstone Gourd)

Limonite/Goethite Concretion (FeOO(H))

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)

Sandstone (with potential trace fossils)

Clastic sedimentary rock (primarily SiO2)

Petrified Wood

Silicified Wood / Chalcedony (SiO2)

Chert (Chert Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Vesicular Sandstone

Clastic Sedimentary Rock (Sandstone)

Bituminous Coal

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

Fossiliferous Limestone (Coquina / Shell Limestone)

CaCO3 (Calcium Carbonate)

Sandstone (likely Graywacke or Lithic Sandstone)

Arenite / Wacke (SiO2 based with lithic fragments)

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (White Chert)

Microcrystalline Quartz (SiO2)