Mineral Description (Anthropogenic Material)

Banded Quartzite or Gneissic Pebble

Quartzite with mafic inclusions (SiO2) or Banded Gneiss

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Orange chromium diopside (likely tumbled)

Diopside, CaMgSi₂O₆; orange color may reflect iron-rich composition or surface treatment/inclusion

Fossilized shell fragment

Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment

Gneiss

Foliated quartzo-feldspathic gneiss, commonly containing biotite or amphibole

Banded Calcite (often sold as 'Mexican Onyx')

Calcite (Calcium Carbonate, CaCO3)

Coarse-grained mica-bearing metamorphic rock, likely schist

Mica schist, probably muscovite–biotite schist with quartz and feldspar

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Red Granite

Felsic Plutonic Rock (Granite)

Sandstone (with Feldspathic/Arkose qualities)

Arenite (primarily SiO2 with KAlSi3O8 components)

Weathered brown mineralized rock

Likely iron-stained quartzite or quartz-rich metamorphic rock; exact identification requires testing

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2)

Weathered chert or silicified limestone nodule

Microcrystalline quartz (SiO₂), possibly replacing limestone; exact identification requires testing

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)

Granodiorite / Granite

Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)

Galena-rich sulfide specimen

Galena (lead sulfide, PbS), possibly with sphalerite and oxidized sulfides

Tumbled quartz-rich rock, likely milky quartz with feldspar

Quartz (SiO₂), probably with feldspar and minor iron-oxide inclusions

Tumbled yellow jasper or serpentine

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Lemon Quartz

Silicon Dioxide (SiO2)

Carnelian

Chalcedony (SiO2) with iron oxide impurities

K2 stone (azurite–granite)

Biotite granite hosting blue azurite (Cu₃(CO₃)₂(OH)₂), often with malachite and quartz

Slate

Metamorphic Rock (Fine-grained)

Sandstone

Arenite (predominantly SiO2 with iron oxides)

Banded Sandstone

Arenite with Liesegang banding

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Quartz Breccia with Iron Staining

Tectonic or Sedimentary Breccia (SiO2 with Fe2O3)

Calcite specimen

Calcite (calcium carbonate, CaCO₃), likely crystalline limestone or cave-calcite aggregate

Tumbled blue chalcedony (likely common blue quartz)

Microcrystalline quartz, SiO₂; chalcedony variety

Polished/tumbled jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities

Tumbled honey calcite

Calcite (CaCO₃), likely iron-stained variety

Tumbled carnelian (likely)

Orange-red chalcedony, microcrystalline quartz (SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Sapphire (Rough)

Corundum (Al2O3)

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Quartz Pebble

Silicon Dioxide (SiO2)

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Pink Quartz (Rose Quartz)

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Rose Quartz

Silicon Dioxide (SiO2)

Chert (Jasper variation)

Chert (Silicate mineral, SiO2)

Labradorite

Labradorite (Plagioclase Feldspar Series: (Ca,Na)(Al,Si)4O8)