Mixed

Likely quartz-bearing mineral aggregate

Quartz (SiO₂), possibly mixed with mica or feldspar

Limonite (Ironstone Concretion)

Limonite (Hydrous Ferric Oxides mixed with Goethite)

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

Dalmatian Stone (commonly called Dalmatian Jasper)

Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Educational Geologic Collection

Mixed Mineral and Rock Collection (Various compositions)

Concrete

Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)

Chrysocolla

Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O

Pea Gravel / River Gravel

Unconsolidated Clastic Sedimentary Aggregate

Glauconitic Sandstone

Glauconitic Sandstone (Quartz with Glauconite)

Pink Granite

Phaneritic Plutonic Felsic Rock (K-feldspar rich)

Mixed tumbled gemstone collection

Varied minerals, likely including amethyst, sodalite/lapis lazuli, quartzite or aventurine, jasper, and agate/chalcedony

Mixed rock and mineral specimen collection

Multiple species, likely quartz (SiO₂), calcite (CaCO₃), feldspar, chert, and assorted volcanic/sedimentary rocks

Granite and Mixed Landscape Gravel

Plutonic Igneous Rock / Weathered Alluvium

Mixed Mineral Assortment (Pyrite, Kyanite, Agate, Jasper)

FeS2 (Pyrite), Al2SiO5 (Kyanite), SiO2 (Agate/Jasper)

Sandstone and Mixed Rock Assemblage

Clastic Sedimentary Rock / Quartz Arenite

Jasper and Mixed River Pebbles

Microcrystalline Quartz (Chalcedony / Jasper)

Petrified Wood and Mixed Rocks

Silicified Wood (SiO2)

Mixed River Stones and Minerals

Mixed Silica-rich Stones (Quartz, Agate, Jasper, Sandstone, Dalmation Stone)

Mixed Gemstone and Mineral Collection

Silicon Dioxide (SiO2) based minerals and others

Mixed Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Conglomerate (Greenstone/Pebble Conglomerate)

Polymictic Conglomerate

Granite (Pink/Alkali Feldspar Granite)

Plutonic Igneous Rock (Granite)

River Rock

Mixed composition, often quartzite, sandstone, or basalt

Common River Pebbles and Stones

Mixed natural stream gravel / siliciclastic pebbles

Siltstone

Siltstone (composed of mixed silicate minerals and clay)

River Rocks and Pebbles

Mixed Silica-rich Sediments (SiO2 based)

Bauxite

Bauxite (Al2O3·2H2O mixed with iron oxides)

Granite

Granite; primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende

Slag

Ferrous slag (by-product of iron smelting)

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Epidotite (Unakite variety)

Epidotized Granite (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Amazonite in Quartz

K(AlSi3O8) - Potassium Feldspar with Quartz (SiO2)

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Mixed river pebbles and quartz-rich specimens

Polymictic fluvial gravel; likely quartz, quartzite, chert, and weathered feldspathic rocks

Mixed river-worn rock and mineral collection

Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble

Pink Granite

Granite (Felsic Plutonic Igneous Rock)

Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidote and Quartz)

Pink Granite

Phaneritic intrusive igneous rock with dominant Alkali Feldspar

Pink Granite

Felsic Plutonic Rock (Granite)