Mixed: Igneous And Sedimentary

Blue-gray granite or granitic gneiss pebble

Granite, chiefly quartz, feldspar, and biotite/amphibole

Tumbled granite pebble

Granite, primarily quartz–feldspar–mica aggregate

Polished granite cobble

Granite, typically quartz–feldspar–biotite granite

Tumbled granite or granitic gneiss

Granite; primarily quartz, alkali feldspar, plagioclase, and mica

Coarse-grained igneous rock, likely granitic pegmatite or weathered granite

Granite/pegmatitic granite; chiefly quartz (SiO₂), feldspar, and dark mica or amphibole

Granodiorite

Phaneritic-textured Intrusive Granodiorite

Mixed Mineral Bead Bracelet

Polycrystalline and Monocrystalline Silicates/Oxides (Quartz, Howlite, Hematite)

Lapis Lazuli (Low-grade)

Lapis Lazuli (Aggregate of Lazurite, Calcite, and Pyrite)

Tumbled yellow-brown quartzite or jasper

Quartzite, predominantly microcrystalline quartz (SiO₂), possibly iron-stained jasper

Polished hematite

Hematite (Fe₂O₃), likely a tumbled iron-oxide specimen

River-rounded landscaping pebbles

Mixed alluvial gravel; commonly quartzite, granite, basalt, sandstone, and quartz

Mookaite Jasper

Silicified radiolarite (SiO2)

Gravel and Pebbles

Unconsolidated rock fragments (clastic sediment)

Mookaite Jasper

Silicified Radiolarite (SiO2)

Garnet, likely almandine–spessartine

Garnet-group nesosilicate; commonly almandine Fe₃Al₂(SiO₄)₃ or spessartine Mn₃Al₂(SiO₄)₃

Mixed Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Mahogany Obsidian

Volcanic glass containing Magnetite/Hematite

Mixed stream gravel and cobbles

Polylithic alluvial deposit; individual clasts are not identifiable at this resolution

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Mixed polished gemstones and minerals

Likely agate/chalcedony (SiO₂), quartz, jasper, and possibly aventurine or obsidian; exact identification requires individual testing.

Polished brown jasper

Jasper (microcrystalline quartz, SiO₂), likely iron-oxide-rich variety

Epidote in Matrix (Unakite-like Rock Fragment)

Epidote (Ca2(Al,Fe)3(SiO4)3(OH)) / Altered Metamorphic Pebble

Epidote in Quartz

Epidote (Ca2(Al2,Fe3+)3(SiO4)3(OH)) / Quartz (SiO2)

Weathered quartz-rich river pebble

Likely altered granite or granitic gneiss, composed mainly of quartz, feldspar, and minor mica/iron oxides

Black granite (likely polished gabbro or diabase)

Granitoid rock dominated by feldspar, quartz, and dark mafic minerals; exact identification requires testing

Granite (Pink/Alkali Feldspar Granite)

Plutonic Igneous Rock (Granite)

Jasper and Quartz Pebble

Silicon dioxide (SiO2) microcrystalline quartz variety

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Polymictic conglomerate

Lithified polymictic conglomerate; clasts likely quartzite, granite, and volcanic rock in a dark matrix

Bauxite (Iron-stained Chert / Ironstone Aggregate)

Hydrous aluminum oxide mixture (mainly Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Goethite α-Fe3+O(OH))

Yellow Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Devil's Toenail (Fossil Oyster)

Gryphaea arcuata (Calcium Carbonate, CaCO3)

Mixed river-worn rock collection

Uncertain; likely quartzite, sandstone, basalt, and weathered granite or gneiss

Jasper Rose Quarts / Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Rounded weathered stone, likely basaltic or volcanic rock

Indeterminate fine-grained mafic volcanic rock; possibly basalt or andesite

Quartz with Feldspar

Silicon Dioxide (SiO2) with Potassium Feldspar (KAlSi3O8)

Glauconitic Sandstone

Glauconitic Sandstone (Quartz with Glauconite)

Tumbled Agate

Silicon Dioxide (SiO2)

Siltstone

Siltstone (composed of mixed silicate minerals and clay)