Mixed (Sedimentary, Igneous, And Metamorphic)

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Tumbled black tourmaline (likely schorl)

Schorl, sodium–iron tourmaline: NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Conglomerate (pebble-to-cobble gravel)

Polymictic conglomerate; clast-supported conglomerate in a sandy or silty matrix

Mixed sedimentary rock and mineral specimens

Predominantly limestone, chert, sandstone, and iron-oxide-bearing clasts; exact identification requires testing

Quartz and Mixed Sedimentary Rocks

Silicon Dioxide (SiO2) mixed with various clastic sedimentary lithologies

Eudialyte

Eudialyte (Na4(Ca,Ce)2(Fe2+,Mn,Y)ZrSi8O22(OH,Cl)2)

Quartz with Chlorite / Greenschist

Quartz vein in Greenschist (SiO2 with Chlorite group minerals)

Concrete Paver (Artificial Cementitious Rock)

Hydrated Portland Cement Aggregate

Weathered quartz-rich metamorphic rock

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

Tumbled granite or granitic gneiss

Granite, primarily quartz, alkali feldspar, plagioclase, and dark biotite/amphibole

Weathered quartz-rich rock, possibly granite or granitic pegmatite

Indeterminate quartz–feldspar aggregate; likely granite/pegmatite

Pink granite

Coarse-grained granitic rock, chiefly orthoclase microcline feldspar, quartz, and dark biotite/amphibole

Gabbro (Water-worn pebble)

Gabbro

Pegmatite with Lepidolite and Feldspar

Pegmatite (containing K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 and KAlSi3O8)

Granite

Coarse-grained granitic rock, primarily quartz, alkali feldspar, plagioclase, and dark biotite/amphibole

Weathered granite fragment

Granite, chiefly quartz, feldspar, and mica

Milky quartz

Quartz (silicon dioxide, SiO₂)

Mixed polished gemstones and minerals

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

Pegmatite

Igneous Pegmatite (Quartz, Feldspar, Micas)

Likely quartz-bearing mineral aggregate

Quartz (SiO₂), possibly mixed with mica or feldspar

Weathered iron-rich rock, possibly hematite-bearing chert

Hematite (Fe₂O₃), likely mixed with silica and iron oxides

African Turquoise

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

Diorite

Intermediate Phaneritic Igneous Rock

Lunar Meteorite

Lunar Feldspathic Breccia

Pink Granite

Phaneritic Quartz-Feldspar Plutonic Rock

Conglomeratic gravel / lithified alluvial deposit

Polymictic conglomerate or pebble-rich sandstone (likely weakly cemented)

Dearest Ring (Gemstones)

Mixed Gemstones: Diamond (C), Emerald (Be3Al2Si6O18), Amethyst (SiO2), Ruby (Al2O3), Sapphire (Al2O3), Topaz (Al2SiO4(F,OH)2)

Pegmatite

Granitic Pegmatite

Mixed River Stones and Agates

Mixed Silicates and Ironstones (primarily SiO2 and Fe2O3)

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Garnet (likely Almandine, Pyrope, or a blend)

Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)

Asphalt fragment

Bituminous concrete

Gemstone bead necklace, likely mixed tourmaline and quartz

Probable schorl/dravite tourmaline with quartz or smoky quartz; exact identification requires testing

Polymict conglomerate (pebble conglomerate)

Clastic sedimentary rock; rounded pebble and granule clasts in a finer-grained matrix

Pyrite-bearing Rock

Iron Sulfide (FeS2) associated with host rock

Sandstone (likely Greywacke or Siltstone variety)

Arenite / Siltstone (primarily SiO2)

River gravel and cobbles

Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone

Granite Pebble

Granite

Black Tourmaline (Schorl)

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Banded Amethyst

Silicon Dioxide (SiO2) with iron impurities

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)