Sedimentary (Base), Then Artificial

Coquina / Shelly Limestone

Bioclastic Limestone (composed of CaCO3)

Chert (River Stone/Pebble)

Chert (SiO2)

Sandstone

Arenite (primarily SiO2)

Limestone

Calcium Carbonate (CaCO3)

River Stone (River Pebble)

Stream-rounded clast (likely Quartzite or Siltstone)

Sandstone (specifically Double Arch in Arches National Park)

Entrada Sandstone

Sandstone (with banding/weathering)

Clastic Sedimentary Rock (primarily SiO2)

Fossilized Coral (Petoskey Stone or similar Favosites)

Hexagonaria percarinata / Favosites (Silurian-Devonian Coral)

Ironstone (likely Limonite or Goethite)

Ferruginous sedimentary rock (FeO(OH)·nH2O)

Biotite Schist

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

Boulder Opal

Precious Opal in Ironstone (Amorphous Hydrated Silica, SiO2·nH2O)

African Turquoise

Teal Jasper (Macro-crystalline Quartz/Sio2 + Inclusions of Copper, Iron, and Manganese)

Ferruginous Breccia

Breccia with Iron-rich (Hematite/Goethite) Matrix

Biotite Schist

Biotite-rich Schist

Kyanite (within Quartz)

Kyanite (Al2SiO5) in crystalline Quartz base (SiO2)

Mica Schist

Mica Schist (primarily Muscovite and Biotite KAl2(AlSi3O10)(OH)2)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium and/or Vanadium impurities

Crushed Limestone and Calcite

Calcium Carbonate (CaCO3)

Conglomerate

Conglomerate (Clastic Sedimentary Rock)

Limestone (Fossiliferous)

Sedimentary Carbonate Rock (CaCO3)

Yellow Chert

Sedimentary cryptocrystalline quartz (SiO2)

Mica Schist

Schist (Muscovite/Biotite Schist)

Chalcedony with Druzy Quartz Geode

Silicon Dioxide (SiO2)

Zebra Jasper

Opaque microcrystalline Quartz (SiO2) with impurities

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Ironstone (Limonitic Sandstone)

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

Conglomerate

Conglomerate (SiO2, Al2O3, Fe2O3, CaCo3)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Chert (specifically Yellow/Common Opal or Jasper mixture)

Silicon Dioxide (SiO2)

Kyanite

Kyanite (Al2SiO5)

Schist

Mica Schist

Schist (Biotite Schist)

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

Geode or Concretion

Silica-based Concretion / Quartz Geode

Glauconitic Sandstone

Glauconitic arenite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2

Mica Schist (with Muscovite mica)

Mica Schist (KAl2(AlSi3O10)(OH)2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Fossilized Coral (Petoskey-style)

Hexagonaria percarinata (Fossilized Rugose Coral)

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Rough Precious Opal

Hydrated Silica (SiO2·nH2O)

Sandstone

Arenite (SiO2 based with mineral cement)

Chert (Field Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Variety)

Microcrystalline Quartz (SiO2)