Indeterminate

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

Likely fossilized shell or bone fragment

Indeterminate bioclast; possibly silicified/bioapatite-bearing shell or bone

Uncertain fine-grained rock or mineral-bearing specimen

Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains

Likely weathered iron-rich rock or mineral fragment

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

Likely weathered brown rock or iron-rich mineral specimen

Indeterminate from image; possible limonite/goethite-rich material

Rounded gray river pebble

Indeterminate; likely weathered basalt, andesite, or fine-grained graywacke

Uncertain small tan mineral/rock fragment

Indeterminate from image; possibly feldspar-rich rock or calcite

Weathered quartz-rich rock, possibly chert or quartzite

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

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, possibly altered granite

Small weathered pebble, possibly limestone

Indeterminate carbonate-rich rock; likely calcite-bearing limestone

Likely weathered river pebble

Indeterminate lithology; possibly fine-grained sandstone, siltstone, or chert

River Pebble (Greywacke / Basalt Pebble)

Indeterminate Rounded Pebble (composed of quartz, feldspar, or mafic minerals)

Fossilized turtle shell fragment

Testudines indeterminate; shell bone permineralized with silica/carbonate minerals

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

Possible blue sapphire

Corundum (Al₂O₃), possibly blue sapphire

Small pale pebble, possibly quartz-rich rock

Indeterminate from image; likely quartz-bearing pebble (SiO₂)

Weathered geode or concretion (uncertain)

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

Likely fossilized tooth fragment

Indeterminate vertebrate tooth; species cannot be identified from the image

Possible ironstone concretion or weathered sulfide-bearing rock

Indeterminate from the photograph; possibly goethite/limonite-rich ironstone

Fossilized tooth, possibly a shark tooth

Indeterminate fossil tooth; species cannot be identified from this view

Likely rough mineral specimen (possibly mica-rich)

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

Possible fossilized bone fragment

Indeterminate fossil bone; no species can be identified from this image

Weathered, iron-stained rock (likely metamorphic)

Indeterminate from photograph; possibly quartz-rich gneiss or schist

Small reddish-brown mineral fragment, likely quartz-bearing rock

Indeterminate; possibly iron-stained quartz or feldspar-rich stone

Small dark mineral/rock fragment

Indeterminate; possibly biotite-rich schist, graphite, or metallic sulfide

Rounded, weathered pebble (likely quartz-rich rock)

Indeterminate from the image; possibly quartzite or quartz-rich sandstone

Unidentified rough rock fragment

Indeterminate; no diagnostic mineral or texture can be confirmed from the image

Quartz-rich sandstone or chert fragment

Indeterminate siliciclastic rock; likely quartz arenite or weathered chert

Tooth or bone fragment (likely animal tooth)

Indeterminate vertebrate tooth; possibly a small mammal or fish tooth

Polished river pebble

Indeterminate fine-grained fluvial clast, likely sandstone or chert

Rounded iron-rich stone or concretion

Indeterminate; possibly hematite-/goethite-bearing sandstone or an ironstone concretion

Rounded greenish river pebble

Indeterminate; possibly weathered greenstone, basalt, or serpentinized ultramafic rock

Weathered quartz-bearing rock fragment

Indeterminate; likely quartz-rich granite, gneiss, or pegmatitic rock

Unidentified pale mineral or rock surface

Indeterminate from image; possibly a small quartz or feldspar grain

Possible fossilized shell or fossil fragment

Indeterminate; possibly a small brachiopod or gastropod fossil in mineralized matrix

Rounded weathered stone

Indeterminate; likely a fine-grained mafic rock such as basalt or andesite

Likely weathered metamorphic rock (possibly schist or gneiss)

Indeterminate; probable mica-rich quartz–feldspar metamorphic rock

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate (SiO₂ with feldspar minerals)

Weathered sandstone or altered volcanic rock

Indeterminate; likely quartz–feldspar-rich sandstone, possibly tuff