Igneous Or Sedimentary (Water Worn)

Shungite

Non-crystalline carbon (allotrope of carbon)

Dalmation Stone

Peralkaline Rock (SiO2 with Arfvedsonite)

Pumice

Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)

Pumice

Vesicular volcanic glass (Amorphous silica mixed with various oxides)

Scoria (Lava Rock)

Extrusive Igneous Scoria (Vesicular Basalt)

Pumice

Pumice (a highly vesicular volcanic glass)

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Pumice

Pumice (a highly vesicular extrusive igneous rock, primarily amorphous silica)

Hematite Nodules (Moqui Marbles style)

Iron Oxide (Fe2O3)

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Granitic Pegmatite

Granite Pegmatite (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Muscovite)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Greywacke)

Arenite/Greywacke (SiO2 major)

Orange Calcite

Calcium Carbonate (CaCO3)

Ironstone (likely Limonite or Goethite nodule)

Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Geode (unopened nodule)

Silicon Dioxide (SiO2) Nodule

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Opal

Hydrated amorphous form of silica (SiO2·nH2O)

Common Opal

Hydrated amorphous form of silica (SiO2·nH2O)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Granite Pebble (Salt and Pepper Granite)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Sandstone (Greywacke/Siltstone variant)

Clastic Sedimentary Rock (composed primarily of Quartz SiO2 and Feldspar)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Garnet

Almandine formula: Fe3Al2(SiO4)3

Lava Rock (Scoria)

Scoria (Basaltic Scoria)

Glauconitic Sandstone

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

Obsidian

Obsidian (Volcanic Glass)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Sandstone (with garnet granules)

Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)

Sandstone (with potential trace fossils)

Clastic sedimentary rock (primarily SiO2)

Granite Pebble

Felsic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)

Blue Apatite

Fluoroapatite (Ca5(PO4)3F)

Pyrite

Iron Sulfide (FeS2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Dalmatian Jasper

Dalmatian Stone (a microcrystalline quartz and feldspar rock with arfvedsonite)

Conglomerate

Conglomerate (clastic sedimentary rock)

Conglomerate

Conglomerate (clastic sedimentary rock)