Rock

Agate Geode

Silicon Dioxide (SiO2)

Rock Crystal Quartz

Silicon Dioxide (SiO2)

Basalt with Quartz Vein

Basaltic rock with hydrothermal SiO2 filling

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic volcanic rock; commonly basalt (plagioclase, pyroxene, and possible olivine)

Garnet Schist

Mica Schist with Almandine (Fe3Al2(SiO4)3)

Porphyritic Basalt

Porphyritic Basalt (with Plagioclase phenocrysts)

Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)

Porphyritic Basalt (Mafic Extrusive)

Pumice

Pumice (Amorphous volcanic glass)

Quartz Geode

Silicon Dioxide (SiO2)

Serpentinite

Antigorite, Lizardite, and Chrysotile (Mg3Si2O5(OH)4)

Bauxite (Laterite Clay)

Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

River Stone (likely Basalt or Greywacke)

Basalt with mineral veining

Basalt

Basalt (Mafic volcanic rock)

Sandstone

Arenite

Dark, veined metamorphic rock (possibly gneiss or schist)

Undetermined from the photograph; likely a foliated, quartz-veined metamorphic rock

Shale (with Iron Staining)

Argillaceous mudstone / Shale

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Yellow Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide, SiO2)

Sandstone (lithic wacke)

Arenite / Lithic Wacke (mostly SiO2 with rock fragments)

Weathered sandstone

Quartz-rich sandstone, locally iron-oxide stained (SiO₂-dominant)

Lapis Lazuli

Lapis Lazuli (Complex rock primarily composed of Lazurite (Na,Ca)8[(SO4,S,Cl)2|(AlSiO4)6], Calcite, and Pyrite)

Quartz-veined weathered host rock

Quartz (SiO₂) in a likely altered limestone or metamorphic carbonate host

Weathered iron-rich rock, likely limonite/goethite-bearing laterite

Limonite–goethite aggregate, commonly approximated as hydrated iron oxides (FeO(OH)·nH₂O)

Rugose Coral

Order Rugosa

Peach Moonstone

Potassium Aluminum Silicate (KAlSi3O8)

Dalmatian Stone

Dalmatian Jasper (Aplite rock composition)

Sandstone (Wonderstone)

Clastic Sedimentary Rock (primarily SiO2)

Granite

Felsic intrusive igneous rock

Small gray rock fragment

Undetermined; likely a common silicate-rich stone or concrete/road aggregate fragment

Granite Pebble

Intrusive Igneous Rock

Fossilized Ammonite

Ammonoidea subclass

Limestone (River Pebble)

Calcium Carbonate (CaCO3)

Fossils in Limestone (Crinoid / Marine Invertebrate Fossil)

Fossiliferous Limestone (containing Crinoidea / Brachiopoda)

Limestone (Weathered Pebble)

Calcium Carbonate (CaCO3) / Limestone

Quartz-Veined Sandstone

Quartz-veined Arenite

Sandstone and Conglomerate pebbles

Sedimentary clastic rock

Milky Quartz (Quartz Vein)

Silicon Dioxide (SiO2)

Weathered iron-rich rock fragment

Likely limonite/goethite with hematite and iron-bearing silicates; exact identification requires testing

Rough turquoise-bearing rock (probable turquoise matrix)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a host-rock matrix

Unknown Rock

Unknown

Basalt

Extrusive igneous rock

Iron-stained quartzite (likely)

Quartz-rich quartzite, predominantly SiO₂, with iron-oxide staining