Sedimentary Rock (Metamorphosed)

Agate (or Chalcedony)

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Sandstone (Greywacke)

Arenite / Wacke (Mainly SiO2 with various lithic fragments)

Sandstone

Arenite (primarily SiO2)

Coquina Limestone (Fossiliferous Limestone)

Calcareous bioclastic sedimentary rock (CaCO3)

Conglomerate (Red Sandstone variety)

Clastic Sedimentary Rock (Conglomeratic Sandstone)

Dragon Stone

Ohko Stone (Argillaceous sedimentary rock)

Bituminous Coal

Bituminous coal (Organic Sedimentary Rock)

Jasper Conglomerate (Puddingstone)

Jasper Conglomerate (Siliceous Sedimentary Rock)

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Coquina or Fossilized Shell Aggregate

Calcareous bioclastic sedimentary rock (CaCO3)

Quartz Conglomerate

Quartz Conglomerate (clastic sedimentary rock)

Ferruginous Sandstone

Clastic Sedimentary Rock (Iron-rich)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

Jasper Conglomerate (specifically Puddingstone)

Jasper Conglomerate (Siliceous sedimentary rock)

Lignite (Brown Coal)

Humic Lignite (Carbonaceous sedimentary rock)

Mexican Crazy Lace Agate

Silicon Dioxide (SiO2) with iron and aluminum inclusions

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Limestone

Calcium Carbonate (CaCO3)

Limestone with Weathering Rind

Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone

Sandstone

Arenite (SiO2 + various cementing minerals)

Limestone Pebble

Calcium Carbonate (CaCO3)

Chert (Septarian or Nodular variety)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Limestone

Calcium Carbonate (CaCO3)

Blue Chalcedony

Chalcedony (Silicon Dioxide, SiO2)

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)

Mica Schist

Mica Schist (primarily Muscovite and Biotite composition)

Sandstone (Ferruginous)

Arenite (variable SiO2 with Fe2O3 staining)

Biotite Schist

Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Sandstone (Quartz-rich)

Arenite (SiO2 based)

Gneiss (with Mica and Quartz)

Gneissic Metamorphic Rock

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Gneiss (Metamorphic Rock)

Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)

Druzzy Quartz on Matrix

Silicon Dioxide (SiO2)

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)

Sandstone (Ferruginous)

Sandstone (SiO2 with iron oxide inclusions)

Sandstone (Ferruginous)

Arenite (with Hematite/Limonite cement)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)