Unknown (Likely Sedimentary Or Metamorphic)

Pearl

Pearl; primarily aragonite (CaCO₃) in nacre

Weathered greenish-brown rock, likely serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with olivine, pyroxene, magnetite, or carbonate

Garnet in Matrix (likely Almandine Garnet)

Almandine (Fe3Al2(SiO4)3)

Mixed stream gravel and cobbles

Polylithic alluvial deposit; individual clasts are not identifiable at this resolution

Weathered granitic gneiss

Foliated quartz–feldspar–mica gneiss; compositionally similar to granite

Tumbled quartz-rich stone, likely iron-stained quartzite

Quartzite, predominantly SiO₂, with iron-oxide staining and possible mica/minor feldspar

Red Jasper

SiO2 (Silicon Dioxide with Iron inclusions)

Gneiss (specifically a Granitic Gneiss)

Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Polished banded stone, likely zebra jasper

Zebra jasper (banded microcrystalline quartz, chiefly SiO₂, with iron-oxide and carbonate impurities)

Likely banded gneiss or mica-rich metamorphic pebble

Gneiss; composition likely quartz, feldspar, and biotite/muscovite mica

Assorted gemstone jewelry

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

Weathered gneissic or granitic rock

Quartz–feldspar–biotite gneiss (tentative; possibly weathered granite)

Tumbled mica-rich stone, likely muscovite schist

Muscovite-bearing quartz schist; chiefly muscovite mica, quartz, and possibly feldspar

Biotite-bearing schist (likely mica schist)

Mica schist, commonly quartz + biotite ± muscovite; composition varies

Pink-and-black feldspar-rich metamorphic rock, likely gneiss

Biotite–feldspar gneiss, possibly pegmatitic granite-derived

Polished white calcite (likely satin spar variety)

Calcite, calcium carbonate (CaCO₃)

Polished brown gemstone, likely jasper or bronzite

Jasper: microcrystalline SiO₂; possible bronzite: (Mg,Fe)SiO₃

Rounded gray river pebble

Likely quartz-rich metamorphic or igneous pebble; exact identification requires testing

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Pelitic schist fragment, possibly garnet-mica schist

Muscovite–biotite schist with quartz; possible almandine garnet

Mixed mineral and rock specimen collection

Assorted silicates, carbonates, oxides, and sulfides; individual species cannot be reliably identified from this image

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Weathered quartz-rich rock, possibly chert or quartzite

Indeterminate; likely microcrystalline quartz (SiO₂), possibly quartzite or chert

Polished pyrite (likely)

Pyrite, FeS₂; possibly a pyrite-rich sulfide specimen

Quartz-rich breccia or silicified rock

Microcrystalline quartz (SiO₂) with iron-oxide staining and darker host-rock fragments

Quartz with Mica inclusions (likely Schist or Gneiss host)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Pyrite (likely a small gold-bearing pyrite specimen)

Pyrite, iron disulfide (FeS₂)

Weathered iron-rich metamorphic rock, possibly schist or metabasalt

Provisional identification: chlorite–quartz–feldspar schist or altered basalt; exact mineralogy requires testing

Quartzite Pebble

Quartzite

Iron-stained quartz-rich rock, likely quartzite or silicified sandstone

Quartz (SiO₂) with iron-oxide minerals, chiefly hematite/goethite; exact host-rock identification is uncertain from the photograph

Dark gray rock fragment, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and magnetite

Red jasper-bearing rock

Jasper (microcrystalline quartz, SiO₂), likely hematite-rich metachert or ironstone

Tourmaline (likely Schorl)

Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4

Rounded quartz-rich pebble, likely quartzite

Quartzite (microcrystalline quartz, SiO₂), possibly quartz-rich sandstone

Metallic sulfide-bearing pebble, likely pyrite in quartz or host rock

Probable pyrite (FeS₂), possibly with chalcopyrite (CuFeS₂) in a quartz-rich matrix

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite inclusions

Gneiss

Feldspathic biotite gneiss; a high-grade metamorphic rock composed mainly of quartz, feldspar, and mica

Weathered gray pebble, likely quartzite or chert

Quartzite (microcrystalline SiO₂); possibly chert (cryptocrystalline SiO₂)

Mixed tumbled rock and mineral collection

Varied specimens, including probable quartz varieties, jasper, agate, fluorite, rose quartz, amethyst, pyrite, calcite, and others

Gneiss (specifically a weathered or stream-worn specimen)

Gneiss (Foliated Metamorphic Rock)

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)