Mixed (Predominantly Sedimentary And Igneous)

Tumbled granite

Granite, a coarse-grained felsic intrusive igneous rock

Weathered granite

Granite, a coarse-grained felsic intrusive igneous rock

Weathered granite pebble

Granite, a quartz–feldspar–mica plutonic rock

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

Granodiorite

Phaneritic-textured Intrusive Granodiorite

Mixed stream gravel and cobbles

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

Fluorite

Calcium Fluoride (CaF2)

Graphite

Graphite (Native Carbon, C)

Jasper and Quartz Pebble

Silicon dioxide (SiO2) microcrystalline quartz variety

Tumbled polymictic stone, likely jasper-bearing conglomerate

Siliciclastic conglomerate with microcrystalline quartz (jasper/chert) and altered volcanic or feldspathic clasts

Garnet, likely almandine–spessartine

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

Blue Chalcedony

Silicon dioxide (SiO2)

Chalcedony Agate / Carnelian nodules in Matrix

SiO2 (Silicon Dioxide) with iron oxide inclusions

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

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

Mixed Quartz Bracelet (Rose Quartz and Larimar-colored beads)

Silicon Dioxide (SiO2) with various inclusions

Mahogany Obsidian

Volcanic glass containing Magnetite/Hematite

Epidote in Quartz

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

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)

Weathered rounded cobble

Indeterminate lithology; likely weathered sandstone or volcanic rock

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Carved Stone Turtle

Mixed stone carving

Chakra Crystal Bracelet

Mixed Mineral Assortment

Mixed Quartz and Aventurine Chips

Silicon Dioxide (SiO2) with various inclusions

Graywacke

Graywacke Sandstone

Leopard Skin Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Jasper Rose Quarts / Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

Asphalt Concrete

Bituminous Concrete (Anthropic Rock)

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Epidote in Matrix (Unakite-like Rock Fragment)

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

Siltstone

Siltstone (composed of mixed silicate minerals and clay)

Common River Pebbles and Stones

Mixed natural stream gravel / siliciclastic pebbles

River Rock

Mixed composition, often quartzite, sandstone, or basalt