Uncertain

Likely rough mineral specimen (possibly mica-rich)

Indeterminate from the image; a mica such as muscovite or biotite is one possibility

Small pale mineral fragment (possibly quartz)

Unidentified; quartz (SiO₂) is one possibility

Tumbled honey-brown chalcedony (likely agate)

Microcrystalline quartz, SiO₂; chalcedony, possibly iron-stained agate

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Tumbled yellow chalcedony (possibly yellow agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Quartz-rich rock fragment

Unidentified quartz–feldspar-rich rock; exact lithology cannot be determined from the image

Rounded dark-gray rock, likely diorite or andesite

Probable diorite (plagioclase and hornblende/pyroxene); identification is limited by the image

Polished orange agate beads

Chalcedony, microcrystalline quartz (SiO₂), commonly sold as agate

Likely quartz cabochon in a ring

Quartz (SiO₂), possibly clear or milky quartz; identification is uncertain from the photograph

Weathered, iron-stained rock (likely metamorphic)

Indeterminate from photograph; possibly quartz-rich gneiss or schist

Fossiliferous limestone pebble

Calcite-rich limestone (primarily CaCO₃), with possible fossil or fossil-fragment patterns

Quartz-rich rock, possibly milky quartz with iron staining

Predominantly silicon dioxide (SiO₂); exact rock type cannot be determined from the photo

Small banded metamorphic rock fragment

Indeterminate foliated metamorphic rock; possibly mica schist or gneiss

Blue-gray stone fragment, possibly slate or fine-grained basalt

Undetermined; appearance is consistent with slate (fine-grained metamorphosed mudstone), but the image is insufficient for reliable identification.

Likely weathered sandstone fragment

Sandstone, chiefly quartz (SiO₂) grains cemented by silica, calcite, or iron oxides

Rhyolite porphyry

Porphyritic rhyolite, a silica-rich volcanic rock; exact identification requires closer examination

Fine-grained sandstone (tentative)

Quartz-rich sandstone; exact composition cannot be confirmed from the photograph

Dark quartz point (possibly smoky quartz)

Quartz, SiO₂; the dark color may indicate smoky quartz, but the image is insufficient to confirm

Likely clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Possible tektite (natural impact glass)

Impact glass; exact type uncertain from photograph (candidate: moldavite or another tektite)

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

Tumbled green stone, possibly serpentine or prehnite

Provisional identification: serpentine-group mineral, commonly antigorite; alternatively prehnite or green calcite

Tumbled brown chalcedony or jasper

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Granite or granitic rock

Coarse crystalline felsic intrusive rock, chiefly quartz, feldspar, and mica

Yellow calcite (likely honey calcite)

Calcite, CaCO₃

Gray slate or fine-grained shale slab

Slate, a low-grade metamorphic rock composed chiefly of fine-grained mica and quartz; possibly unmetamorphosed shale

Possible carnelian (brown-orange chalcedony)

Microcrystalline quartz, SiO₂; likely iron-stained chalcedony

Rounded quartz-rich pebble

Likely quartzite or quartz-bearing granitoid; predominantly SiO₂ quartz with possible feldspar and mica

Likely silver-gray metallic ore fragment

Unidentified metallic mineral; possibly galena (PbS), but the image is insufficient for a confident identification

Likely polished or naturally smoothed pebble with a pale mineral patch

Undetermined; possibly a dark volcanic rock with a quartz or feldspar inclusion

Fossil-bearing limestone, possibly with crinoid stem sections

Calcite-rich fossiliferous limestone (CaCO₃); the circular features may be fossil fragments

Likely garnet-bearing schist

Mica schist, possibly containing almandine garnet (Fe₃Al₂(SiO₄)₃)

Chalcedony (likely common agate)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly agate

Dark ironstone concretion (probable)

Iron-oxide-rich sedimentary concretion, likely hematite/goethite cementing sand or clay

Granite or granitic pebble

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

Fine-grained, banded rock (possibly gneiss)

Unidentified foliated silicate rock; composition cannot be determined from this close-up

Likely brown mica (biotite) specimen

Biotite, a potassium-iron-magnesium sheet silicate; approximate formula K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂

Likely chert (flint) pebble

Microcrystalline quartz (SiO₂), variety chert

Weathered geode or concretion (uncertain)

Indeterminate; possibly a mineral-filled nodule with a weathered outer rind

Likely metamorphic rock (possibly gneiss or schist)

Undetermined foliated metamorphic rock; exact identification requires closer examination

Fossilized belemnite rostrum (likely)

Belemnitida, a fossil cephalopod guard; exact genus cannot be determined from the image

Tumbled pale-green quartz, likely aventurine or common quartz

Quartz (SiO₂), possibly green aventurine containing fuchsite inclusions