Mixed: Igneous And Sedimentary

Common River Pebbles and Stones

Mixed natural stream gravel / siliciclastic pebbles

River Rock

Mixed composition, often quartzite, sandstone, or basalt

River Rocks and Pebbles

Mixed Silica-rich Sediments (SiO2 based)

Bauxite

Bauxite (Al2O3·2H2O mixed with iron oxides)

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)

Mixed Quartz and Aventurine Chips

Silicon Dioxide (SiO2) with various inclusions

Ruby Zoisite

Anyolite (Calcium aluminium silicate with Chromium/Corundum inclusions)

Weathered granitic rock fragment

Likely granite or granodiorite; quartz–feldspar–mica aggregate

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

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

Chalcedony Agate / Carnelian nodules in Matrix

SiO2 (Silicon Dioxide) with iron oxide inclusions

Fluorite

Calcium Fluoride (CaF2)

Graywacke

Graywacke Sandstone

Leopard Skin Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Polished/tumbled metallic sulfide specimen, likely pyrite

Pyrite (FeS₂), possibly mixed with chalcopyrite or other sulfides

Graphite

Graphite (Native Carbon, C)

Epidote with Quartz

Ca2(Al,Fe)3(SiO4)3(OH) (Epidote) / SiO2 (Quartz)

Greywacke

Lithic Sandstone (Greywacke)

Vesuvianite (Idocrase)

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

Pyrite

Iron Sulfide (FeS2)

Olivine in Quartz/Feldspar Matrix (Peridotite or Granitic Pegmatite)

(Mg,Fe)2SiO4 (Olivine) with Quartz / Feldspar

Epidosite

Epidosite (composed primarily of Epidote and Quartz)

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)

Granite and Mixed Landscape Gravel

Plutonic Igneous Rock / Weathered Alluvium

Bumblebee Jasper

Anhydrite with Sulfur, Hematite, and Orpiment (SiO2/CaSO4 mixture)

Assorted gemstone jewelry

Mixed natural and synthetic gemstone cabochons and faceted stones; individual species cannot be determined reliably from this image

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

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

Pyrite in Matrix (Healers Gold / Pyrite Egg)

Iron Disulfide (FeS2) with Magnetite/Hematite matrix

Pyrite

Iron Disulfide (FeS2)

Polished black stone, likely obsidian or dark basalt

Volcanic glass (obsidian), possibly basalt; exact identification requires testing

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Conglomerate

Conglomerate (clastic sedimentary rock)

Chakra Stone Bracelet

Mixed Mineral Assembly (Scoria, Amethyst, Lapis Lazuli, Turquoise/Howlite, Impression Jasper, Tiger's Eye, Carnelian, Red Jasper)

Sandstone and Mixed Rock Assemblage

Clastic Sedimentary Rock / Quartz Arenite

Garnet crystals

Garnet-group silicates, likely almandine (Fe₃Al₂Si₃O₁₂)

Granite (weathered fragment)

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

Volcanic breccia or conglomeratic volcanic rock

Lithic volcanic breccia; possibly andesitic–basaltic matrix with feldspar-rich clasts

Weathered granite or granitic rock fragment

Granite; chiefly quartz, feldspar, and mica

Asphalt Concrete

Bituminous Concrete (Anthropic Rock)

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Weathered rounded cobble

Indeterminate lithology; likely weathered sandstone or volcanic rock