Igneous, Metamorphic, And Sedimentary (Mixed Assemblage)

Unidentified coarse-grained rock fragments

Likely granite or granitic rock; exact identification is uncertain from the photograph

Feldspar (Granite Pegmatite matrix)

Potassium Feldspar (KAlSi3O8) / Quartz Mixture

Conglomerate

Conglomerate (clastic sedimentary rock)

Agate (Lake Superior Agate variant)

Chalcedony / Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

African Turquoise

African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)

Tumbled quartz pebble, possibly citrine or pale smoky quartz

Quartz (SiO₂), likely microcrystalline/tumbled material

Granite pebble

Granite; primarily quartz, alkali feldspar, plagioclase, and dark mica/amphibole

Polished/rounded granite cobble

Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole

Diorite (River Rock/Cobble)

Intermediate Plutonic Igneous Rock (Diorite)

Pink Granite

Granite (Phaneritic Acidic Igneous Rock)

Sodalite

Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2)

Rounded river pebble

Likely lithic sandstone or weathered quartz-rich rock; exact identification requires testing

Conglomeratic breccia

Clast-supported polymictic conglomerate/breccia, cemented by silica- or carbonate-rich matrix

Bauxite

Aluminium ore (Hydrated aluminium oxides AlOx(OH)3-2x)

Sandstone with Desert Varnish

Arenite with Ferromanganese patina

Lunar Meteorite

Lunar Feldspathic Breccia

Pink Granite

Phaneritic Quartz-Feldspar Plutonic Rock

Graphite-bearing schist (probable)

Graphite–quartz–mica schist; chiefly graphite (C), quartz (SiO₂), and mica

Milky Quartz

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Tumbled metallic sulfide mineral specimen, likely pyrite-bearing ore

Likely pyrite (FeS₂) with associated sulfides and host rock; exact identification requires testing

Weathered quartz-rich metamorphic rock

Likely quartzite or quartz-veined schist; predominantly SiO₂ (quartz) with possible feldspar, mica, and iron-oxide minerals

Quartz

Silicon Dioxide (SiO2)

White Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Pyrite Nodules / Weathered Pyrite

Iron Sulfide (FeS2)

Zoisite with Hornblende

Zoisite (Ca2Al3(SiO4)3(OH)) with Amphibole inclusions

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Quartz

Silicon Dioxide (SiO2)

Quartz (Milky Quartz / Clear Quartz)

Silicon Dioxide (SiO2)

Quartz (Citrine or Iron-Stained)

Silicon Dioxide (SiO2)

Polygenetic Conglomerate (Puddingstone)

Conglomerate (SiO2 matrix with mixed clasts)

Gossan (Iron Cap)

Limonitic Gossan (Fe2O3·nH2O mixed)

Tiger's Eye / Hawk's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Magnetite Ore

Magnetite (Fe3O4)