Sedimentary And Igneous (Mixed)

Mahogany Obsidian

Volcanic glass containing Magnetite/Hematite

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 Mineral Bead Bracelet

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

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)

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

Mixed polished gemstones and minerals

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

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Polished hematite

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

Epidote in Quartz

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

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

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 Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Jasper and Quartz Pebble

Silicon dioxide (SiO2) microcrystalline quartz variety

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Granite (Pink/Alkali Feldspar Granite)

Plutonic Igneous Rock (Granite)

Graywacke

Graywacke Sandstone

Leopard Skin Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Jasper Rose Quarts / Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

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)

Quartz-rich pegmatite (likely rose/iron-stained quartz)

Quartz, SiO₂, in a coarse granitic pegmatite matrix; possibly with feldspar and mica

Concrete aggregate surface

Human-made cementitious composite; primarily calcium-silicate-hydrate cement with mixed silicate aggregate

Glauconitic Sandstone (Greensand)

Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Vesuvianite (Idocrase)

Vesuvianite, Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4

Weathered granitic rock fragment

Likely granite or granodiorite; quartz–feldspar–mica aggregate

Glauconitic Sandstone

Glauconitic Sandstone (Quartz with Glauconite)

Mixed river-worn rock collection

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

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Chalcedony Agate / Carnelian nodules in Matrix

SiO2 (Silicon Dioxide) with iron oxide inclusions

Mixed Quartz and Aventurine Chips

Silicon Dioxide (SiO2) with various inclusions

Graphite

Graphite (Native Carbon, C)

Greywacke

Lithic Sandstone (Greywacke)