Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)

Limonite (Iron Stone)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Slate

Foliated Metamorphic Rock

Chert (Flint)

Microcrystalline Quartz (SiO2)

Dyed Agate

Silicon Dioxide (SiO2)

Fossiliferous Limestone with Crinoid stems

Calcite-rich Biogenic Sedimentary Rock (CaCO3)

Sandstone

Arenite (composed primarily of SiO2)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Chert (Banded)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)

Mica Schist

Crystalline Schist (often containing Muscovite, Biotite, and Quartz)

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone

Sandstone (lithified sand)

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Red Sandstone

Clastic Terrigenous Sedimentary Rock (composed mostly of SiO2 with Fe2O3)

Ferruginous Sandstone

Arenite with Iron-oxide cement

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based clastic rock)

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Sandstone (Quartzose)

Arenite (Formula: SiO2 primary, with various cements)

Gneiss (Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Ferruginous Sandstone

Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)

Ferruginous Quartz on Ironstone

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

Hematite (Iron Ore)

Hematite (Fe2O3)

Dalmatian Stone (Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Sandstone (Ferruginous)

Arenite (Fe-rich)

Bivalve Fossil (Clam/Mollusk)

Class: Bivalvia (Order: Veneroida), Calcium Carbonate (CaCO3)

Phyllite

Phyllite (Foliated metamorphic rock)

Schist (Kyanite Schist)

Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Pink Dyed Agate

Silicon Dioxide (SiO2) with synthetic pigment

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Black Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Blue Chalcedony (Tumbled)

Silicon Dioxide (SiO2)

Quartz (Milky or Druzy Quartz)

Silicon Dioxide (SiO2)

Limonitic Sandstone (Stained Sandstone)

Clastic Sedimentary Rock with Iron Oxide (Limonite/Goethite) staining