Sedimentary (Man Made)

Sandstone Pebble

Arenite (specifically Lithic or Quartz Arenite)

Shale

Argillaceous Sedimentary Rock

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

Sandstone

Arenite (SiO2 based)

Limestone (specifically Bituminous or Carbonaceous Limestone)

Calcium Carbonate (CaCO3) with Organic Impurities

Sandstone

Arenite (SiO2 based)

Shale

Lutaceous sedimentary rock

Granite

Felsic Intrusive Igneous Rock

Granite

Phaneritic plutonic felsic rock

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Sand and Gravel (Quartz-rich)

Unconsolidated fluvial/beach sediment (primarily Silica/SiO2)

Agate (Crazy Lace or Eye Agate)

Silicon Dioxide (SiO2)

Sand Grain (Silica/Quartz Grain)

Silicon Dioxide (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Geode (Unopened)

Silica-rich Concretion (SiO2)

Potassium Feldspar

Orthoclase (KAlSi3O8)

Rhodochrosite

Manganese carbonate (MnCO3)

Hematoid Quartz

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Sandstone (Greywacke)

Arenite / Greywacke Sandstone

Blue Celestite

Strontium Sulfate (SrSO4)

Apatite

Fluorapatite / Chlorapatite (Ca5(PO4)3(F,Cl,OH))

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 primarily)

Bauxite

Bauxite (mixture of hydrous aluminum oxides: Al(OH)3 & AlO(OH))

Rhodochrosite

Manganese Carbonate (MnCO3)

Flint / Chert

Silicon dioxide (Microcrystalline quartz, SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Green Fluorite

Calcium Fluoride (CaF2)

Limonite (Limonitic Sandstone)

Hydrated Iron(III) Oxide-Hydroxide ($FeO(OH)·nH_2O$)

Fluorite

Calcium Fluoride (CaF2)

Satin Spar (Selenite variant)

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

Blue Kyanite

Kyanite (Al2SiO5)

Sandstone

Arenite (SiO2 primarily)

Chert

Microcrystalline Quartz (SiO2)

Fluorite

Calcium fluoride (CaF2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Green calcite (likely)

Calcite, calcium carbonate (CaCO₃)