Indeterminate

Possible weathered quartz-rich rock or iron-stained mineral fragment

Indeterminate; possibly quartz (SiO₂) with iron-oxide inclusions

White quartz pebble or chip

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Tumbled goldstone-like quartz pebble

Likely iron-stained quartz or jasper; exact identification requires testing

Blue-green glassy mineral specimen, possibly chalcedony or slag glass

Uncertain; candidate minerals include chrysocolla-bearing chalcedony or copper-bearing glassy slag

Dark river-worn pebble, likely basalt

Basalt (fine-grained mafic volcanic rock; chiefly plagioclase and pyroxene, with possible olivine and magnetite)

Tumbled purple quartzite or amethyst-bearing quartz

Quartz (SiO₂), likely quartzite; purple coloration may reflect iron impurities or minor amethyst

Fossilized bone or tooth fragment

Mineralized vertebrate bone; exact taxon indeterminate from image

Likely weathered iron-rich stone or concretion

Indeterminate; possibly ferruginous sandstone, ironstone, or a weathered sedimentary concretion

Dark metamorphic rock, likely schist or slate fragment

Indeterminate foliated metamorphic rock; possibly mica schist or slate

Weathered quartz-rich rock or fossil fragment

Indeterminate; likely quartz-bearing sandstone or siliceous fossil material

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, such as granite, or recrystallized quartzite

Rounded greenish pebble

Indeterminate; possibly altered basalt, greenstone, or fine-grained serpentinite

Rounded greenish pebble

Indeterminate; likely weathered quartzite, greenstone, or altered volcanic rock

Rounded pebble, likely quartz-rich river stone

Indeterminate; possibly quartzite, chert, or a weathered quartz-feldspar rock

Rounded river pebble (likely weathered sandstone or chert)

Indeterminate clastic sedimentary rock; possible quartz-rich sandstone

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz (SiO₂) with feldspar and minor mica, or quartzite

Rounded river pebble, likely quartz-rich sandstone or weathered igneous rock

Indeterminate; possibly quartzite, sandstone, or fine-grained granitic rock

Rounded river pebbles, likely quartz-rich sandstone or quartzite

Indeterminate quartz–feldspar rock; possible quartzite or arkosic sandstone

Smooth river pebble, likely quartz-rich sandstone or quartzite

Indeterminate quartz-rich clast; possibly quartzite (mostly SiO₂)

Weathered quartz-bearing rock, possibly calcite vein fragment

Indeterminate; likely quartz (SiO₂) with carbonate minerals such as calcite (CaCO₃)

Small rounded pebble, possibly quartz-rich stone

Indeterminate from image; likely quartz-bearing silicate rock

Uncertain dark gray-brown rock fragment

Indeterminate; possibly weathered chert, serpentine, or iron-stained quartzite

Weathered sandstone or granitic rock fragment

Indeterminate siliciclastic rock; likely quartz–feldspar–mica aggregate

Weathered iron-rich rock fragment

Indeterminate; likely basaltic or mafic rock with iron-oxide staining

Rounded stream cobble

Lithology indeterminate; likely weathered sandstone, quartzite, or granitic rock

Unidentified metallic mineral or metal-like specimen

Indeterminate from image; possibly galena (PbS) or a metallic sulfide

Small pale stone, likely quartzite or limestone fragment

Indeterminate; possible quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)

Tumbled river pebble, likely limestone or weathered chert

Indeterminate carbonate/siliceous pebble; possible micritic limestone or chert

Likely polished brown stone or mineral fragment

Indeterminate from image; possible brown jasper, chert, or agate

Polished black-and-white pebble

Indeterminate; possibly banded agate/chalcedony or black-and-white jasper

Weathered quartz-rich rock, possibly quartzite or granitic fragment

Indeterminate; likely quartzite (mostly SiO₂) or quartz-bearing granitoid

Small tan rock fragment

Indeterminate; possibly quartz-rich sandstone or iron-stained quartz

Fossilized tooth fragment, likely mammalian

Mineralized dentine and enamel; exact taxon indeterminate from the photograph

Ammonite fossil

Fossilized ammonoid cephalopod; likely an indeterminate Jurassic–Cretaceous ammonite

Fossil bone fragment (likely vertebrate bone)

Fossilized vertebrate bone; exact taxon indeterminate from the photograph

Rounded reddish pebble, likely iron-stained sandstone or weathered volcanic rock

Indeterminate; possibly ferruginous sandstone (quartz-rich) or weathered basalt

Likely small iron-rich concretion or weathered mineral fragment

Indeterminate; possibly limonite/goethite-bearing material with quartz or feldspar

Likely weathered sandstone or iron-stained sedimentary pebble

Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone

Fossilized sea-shell fragment, likely belemnite or rudist-like carbonate fossil

Indeterminate calcitic fossil in limestone; possible belemnite rostrum (Belemnitida)

Fossil coral (likely tabulate or colonial coral)

Fossilized colonial coral; exact genus indeterminate from the photograph

Likely rounded dark pebble

Indeterminate; possibly basalt, diabase, or a dark chert/river pebble

Possible weathered sandstone or iron-rich sedimentary rock

Indeterminate; likely quartz-rich sandstone with iron-oxide cement