Sedimentary (Microcrystalline Silicate)

Plume Agate

Silicon Dioxide (SiO2) - Chalcedony Variety

Polished/tumbled jasper, likely ocean jasper or brecciated jasper

Jasper: microcrystalline quartz (SiO₂) with iron oxides and other silicate impurities

Siltstone River Rock

Siltstone (composed of silt-sized particles, silicate minerals)

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Porcelain (Kaolin-based)

Alumina silicate ceramic (composed primarily of Kaolinite: Al2Si2O5(OH)4)

Mica Schist with Biotite or Muscovite

Metamorphic rock rich in sheet silicates

Mixed Tumbled Rocks and Minerals Collection

Mixed Minerals and Rocks (Quartz, Feldspar, Jasper, Agate, Lapis Lazuli, Sodalite, Rose Quartz, Fluorite, etc.)

Common Opal (Green Opal / Pistachio Opal)

Hydrated silica (SiO2·nH2O)

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Coprolite

Fossilized Feces

Serpentine (Serpentinite)

Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Anthracite Coal

Anthracite

Fossiliferous Sandstone / Quartzite Pebble

Sedimentary rock with skeletal fragments (e.g., Paleozoic crinoid/brachiopod fossils)

Brecciated jasper, possibly rainforest jasper or brecciated rhyolite

Brecciated microcrystalline quartz (SiO₂), commonly called jasper; the green portions may contain epidote, chlorite, or iron-bearing silicates, while red-brown areas are typically hematite or other iron oxides

Chalcedony

Silicon Dioxide (SiO2)

Turquoise

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

Clay (as a rock-forming material)

Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Milky Quartz or Moonstone

Silicon Dioxide (SiO2) or Potassium Aluminum Silicate (KAlSi3O8)

Sea Glass

Man-made silicate glass (Amorphous silicon dioxide)

Rounded gray pebble

Indeterminate; likely a water-worn silicate or carbonate pebble

Shiva Lingam

Cryptocrystalline Quartz (Jasperiod Silicate with Iron Oxide inclusions)

Chert / Quartzite

Silicon Dioxide (SiO2)

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Chert / Flint Arrowheads

Cryptocrystalline Quartz (SiO2)

Map Jasper (Picasso Stone)

Metamorphosed Calcium Carbonate (Crystalline Limestone or Marble with Silicate inclusions/impurities)

Quartz-veined Metamorphic Pebble

Silicate-rich metamorphic rock with quartz veins (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Tumbled Agate

Silicon Dioxide (SiO2)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Green Slate (Greenstone)

Foliated Metamorphic Rock (rich in Chlorite/Epidote)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Tumbled Mixed Gemstones and Rocks

Various mineral species including quartz (SiO2) and silicate minerals

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Mixed River Stones and Agates

Mixed Silicates and Ironstones (primarily SiO2 and Fe2O3)

Siltstone with Concretion

Siltstone (composed of hydraulic silicates and quartz particles)

Chert (Flint / Jasper)

Silicon Dioxide (SiO2)

Carnelian / Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Brick

Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)

Chert (Common Opal/Chalcedony variety)

Microcrystalline Quartz (SiO2)