Not A Natural Rock (Man Made Composite)

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)

Tumbled jasper, likely red/brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Smoky Quartz

SiO2 (Silicon Dioxide)

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Turquoise

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

Sandstone (Weathered Coastal Boulder)

Arenite (composed primarily of SiO2)

Tumbled quartzite pebble

Quartzite; predominantly microcrystalline quartz (SiO₂)

Dyed Blue Agate

Silicon Dioxide (SiO2)

Dalmatian Stone

Dalmatian Stone (Felsic Igneous Rock)

Amethyst-rich vesicular volcanic rock (probable amethyst basalt/scoria)

Quartz (SiO₂) in vesicular basaltic volcanic rock; precise identification requires testing

Red Sandstone

Arenite (predominantly SiO2 with Fe2O3 staining)

Golden Healer Quartz

Ferruginous Quartz (SiO2 with Fe2O3 inclusions)

Blue Lace Agate

Silicon Dioxide (SiO2)

Basalt

Basalt

Glauconitic Sandstone (Greensand)

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

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Citrine (Heat-Treated Amethyst)

Silicon Dioxide (SiO2)

Turquoise in Matrix

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

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Turquoise

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

Shale (with minor calcite veining)

Clastic sedimentary rock (primarily clay minerals and quartz)

Slate

Metamorphosed Shale (Fine-grained Foliated Metamorphic Rock)

Fossilized tooth, likely mammalian molar

Indeterminate Mammalia; mineralized dentine and enamel

Hag Stone

Perforated Sedimentary Rock (typically Limestone or Sandstone)

Polished pink banded agate

Microcrystalline quartz (chalcedony), SiO₂

Sunstone

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8

Weathered iron-rich rock, possibly laterite or limonite-bearing stone

Hydrated iron oxides/hydroxides, chiefly limonite-goethite mixture; exact identification requires testing

Blue Banded Agate (Dyed)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Polished Tumbled Fluorite (or Dark Amethyst)

CaF2 (Calcium Fluoride) / SiO2 (Silicon Dioxide)

Magnetite (Lodestone)

Iron(II,III) oxide (Fe3O4)

Gold Nugget

Native Gold (Au)

Weathered pink granite fragment

Granite, chiefly quartz, potassium feldspar, and plagioclase feldspar with minor mica

Turquoise

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

Limonite/goethite-rich ironstone (probable)

Limonite, chiefly hydrated iron oxides; commonly goethite, α-FeO(OH), with possible quartz or host-rock inclusions

Amethyst (Tumbled)

Silicon Dioxide (SiO2) with iron impurities

Asphalt / Bituminous Aggregate

Bituminous mixture (Hydrocarbon-based sediment)

Black Onyx

Silicon Dioxide (SiO2) - variety of Chalcedony

Turquoise

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

Turquoise

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

Clear quartz sphere

Quartz (silicon dioxide, SiO₂), likely rock crystal or low-grade milky quartz

Magnetite (potentially as a Lodestone or within Ironstone)

Magnetite (Fe3O4)

Greywacke Siltstone Pebble / Concretionary River Pebble

Siltstone / Argillite (Fine-grained Sedimentary Rock)