Mixed

Mixed river-worn rock and mineral collection

Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble

Tumbled chert or flint

Microcrystalline quartz (SiO₂), commonly chalcedony with possible iron-oxide inclusions

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica, with iron-oxide weathering

Mixed beach pebbles and shell fragments

Mostly carbonate rocks, likely limestone/calcarenite, with mollusk-shell bioclasts; exact species cannot be determined visually

Alluvial stream gravel (mixed rock specimens)

Polymictic fluvial deposit; likely mixtures of quartzite, sandstone, shale, chert, basalt, and granite-derived minerals

Mixed river pebbles and quartz-rich specimens

Polymictic fluvial gravel; likely quartz, quartzite, chert, and weathered feldspathic rocks

Concrete

Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)

Mixed tumbled gemstone and mineral lot

Primarily quartz varieties (SiO₂), feldspar, beryl/chalcedony, and other unidentified silicate minerals

Tumbled amber-colored chalcedony and quartz

Chalcedony (microcrystalline SiO₂), quartz (SiO₂), possibly carnelian or citrine; one piece may be druzy chalcedony

Mixed tumbled stones, likely rose quartz and purple quartz/amethyst

Quartz (SiO₂), including amethyst and probable rose quartz; exact identification is uncertain from the blurred image

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Pea Gravel / River Gravel

Unconsolidated Clastic Sedimentary Aggregate

Glauconitic Sandstone

Glauconitic Sandstone (Quartz with Glauconite)

Pink Granite

Phaneritic Plutonic Felsic Rock (K-feldspar rich)

Polished gemstone beads, likely mixed agate or jasper

Likely microcrystalline quartz (SiO₂); exact varieties cannot be confirmed from the photograph

Mixed gemstone bead bracelet, likely including blue quartz and dark-colored stones

Quartz (SiO₂) beads; other bead materials cannot be identified reliably from the image

Rounded pebble, likely mixed lithology

Lithology uncertain; possibly a fine-grained metamorphic or volcanic rock with a quartz-rich/pink feldspar vein or inclusion

Mixed beach-stone collection, primarily quartz-rich pebbles and possible fossils

Likely quartz (SiO₂), quartzite, chert, and carbonate rock; exact identification is uncertain from the image

Mixed polished/tumbled stones; likely blue calcite, red carnelian, and gray/blue quartz or agate

Probable calcite (CaCO₃), chalcedony/quartz (SiO₂), and iron-colored chalcedony

Mixed beach-stone and tumbled-glass collection

Predominantly uncertain rocks (likely basalt, granite, and quartz-bearing stones) with anthropogenic glass; one possible banded agate or jasper

Mixed small mineral specimens, likely quartz varieties

Uncertain from the image; translucent pieces may be quartz (SiO₂), while golden-brown pieces could be iron-stained quartz or calcite

Mixed river stones; foreground likely sandstone

Quartz-rich sandstone, with associated rounded quartzite/chert and other cobbles

Mixed weathered field rocks, likely sandstone and shale/slate

Indeterminate clastic rocks; possible quartz-rich sandstone with laminated shale or slate

Mixed gemstone bead bracelet, likely lava rock and aventurine/jade-look beads

Basaltic scoria (vesicular basalt), plus probable serpentine, aventurine, or dyed quartzite beads

Mixed River Pebbles and Rock Collection

Polymictic lithic conglomerate, sandstone, and quartz pebbles

Mixed river-worn rock collection

Uncertain; likely quartzite, sandstone, basalt, and weathered granite or gneiss

Mixed rock fragments, likely granite and weathered metamorphic rock

Granite (quartz–feldspar–mica aggregate) with probable schist/gneiss fragments

Mixed rock fragments, likely basalt and weathered granite

Basalt (mafic volcanic rock) and granitic fragments (quartz–feldspar–mica aggregate)

Mixed rounded river pebbles, likely basalt and granite

Basalt (fine-grained mafic rock) and granite/granitoid (quartz–feldspar rock)

Mixed collection of common river stones

Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material

Mixed River Pebbles (including Unakite and Jasper)

Polymineralic geological specimens

Likely gray granite fragment

Granite, composed mainly of quartz, feldspar, and mica

Quartz with Chlorite / Greenschist

Quartz vein in Greenschist (SiO2 with Chlorite group minerals)

Lapis Lazuli

Lapis Lazuli (Complex rock primarily composed of Lazurite (Na,Ca)8[(SO4,S,Cl)2|(AlSiO4)6], Calcite, and Pyrite)

Mixed Rock and Mineral Specimen Set

Multiple (Quartz, Chert, Shale)

Mixed rock specimens; the gray-green piece is likely chlorite-bearing schist, with granite and light-colored quartz-rich rocks also visible

Tentative: chlorite schist (a foliated metamorphic rock); other visible pieces may include granite and quartzite

Mixed collection of quartz-rich rocks and minerals

Quartz (SiO₂), with some pieces possibly containing feldspar or mica; exact identification is uncertain from the image

Mixed rock specimens; likely breccia and quartz-bearing rocks

Indeterminate from the image; the brown, angular clasts may be breccia, with white quartz or calcite pieces nearby

Mixed quartz gemstone bead bracelet

Quartz, silicon dioxide (SiO₂), in varieties including smoky quartz, amethyst, rutilated quartz, and possibly tourmalinated quartz

Mixed rock specimens; likely pink feldspar/quartz and a dark, mica-bearing rock

Tentative visual identification: pink K-feldspar–quartz-rich granite/pegmatite fragments and a dark amphibole- or biotite-rich metamorphic rock; exact identification is uncertain from the image

Faceted gemstones, likely mixed small sapphires or spinel

Corundum (Al₂O₃) or spinel (MgAl₂O₄); exact identification requires testing

Mixed polished gemstone bead bracelet, likely tourmalinated quartz and rhyolite/jasper

Quartz (SiO₂) with black tourmaline (schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) and probable feldspar-rich rhyolite/jasper