Indeterminate

Fossilized shell or coral fragment

Indeterminate biogenic carbonate; likely calcite/aragonite (CaCO₃)

Unidentified pale mineral or rock specimen

Indeterminate; image quality prevents reliable mineral identification

Likely weathered brown rock fragment

Indeterminate; possibly iron-oxide-stained sandstone or laterite

Rounded river pebble, likely weathered sandstone or iron-rich sedimentary rock

Indeterminate siliciclastic sediment; possibly ferruginous quartz sandstone

Dark, weathered stone—possibly basalt or slag

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene)

Rounded gray-green pebble, likely basaltic or metamorphic

Indeterminate mafic rock; possibly basalt, diabase, or greenstone

Dark metamorphic rock, likely schist or slate fragment

Indeterminate; possibly biotite schist, chlorite schist, or slate

Likely weathered quartz-bearing rock

Indeterminate; possibly quartz-rich granite or granitic pegmatite

Weathered yellow-brown rock fragment

Indeterminate; possibly iron-stained sandstone or weathered limestone

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Weathered light-colored rock, possibly quartz-rich granite or quartzite

Indeterminate; likely quartz–feldspar rock (granite) or quartzite

Fossilized bone fragment, possibly vertebra

Fossil bone (mineralized hydroxyapatite; exact taxon indeterminate)

Polished brown stone, possibly jasper or chert

Indeterminate microcrystalline quartz (SiO₂), likely jasper/chert

Rounded sandstone or quartzite pebble

Indeterminate; likely quartz-rich sandstone (SiO₂-dominated)

Rounded quartz-rich pebble, possibly weathered granite or quartzite

Indeterminate; likely quartz (SiO₂)-rich silicate rock

Rounded gray stone, likely quartz-rich sandstone or weathered granite

Indeterminate; probable granitic rock or quartz-feldspar sandstone

Rounded river pebble, possibly quartz-rich metamorphic rock

Indeterminate; likely quartzite or weathered quartz-bearing schist

Rounded river pebble, likely quartz-rich sandstone or weathered quartzite

Indeterminate; probable quartz (SiO₂)-rich clastic rock

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Blue-green tumbled mineral specimen

Indeterminate; possibly chrysocolla, turquoise, or azurite–malachite material

Fossilized shell or coral fragment

Indeterminate calcareous fossil; likely aragonite/calcite (CaCO₃)

Fossilized bivalve or brachiopod fragment

Indeterminate fossil shell, likely calcitic or aragonitic carbonate

Unidentified rock fragments

Indeterminate; likely a weathered, iron-stained silicate rock

Likely fossilized coral fragment

Rugose or tabulate coral fossil; exact taxon indeterminate

Metallic sulfide ore fragment, possibly pyrite-bearing rock

Indeterminate; likely pyrite (FeS₂) in a sulfide-rich matrix

Tumbled blue-gray mineral specimen

Indeterminate; possibly dumortierite quartz, sodalite, or dyed stone

Small polished dark mineral or gemstone fragment

Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline

Weathered brown stone, likely basalt or iron-stained volcanic rock

Indeterminate; possibly vesicular basalt (mafic silicate rock)

Fossil bone fragment, likely mammalian

Fossilized bone; exact taxon indeterminate from image

Weathered stone, likely sandstone or altered volcanic rock

Indeterminate; possibly quartz-rich sandstone or weathered tuff

Fossil-bearing limestone, possibly a crinoid or shell fragment

Calcite (CaCO₃) limestone containing an indeterminate marine fossil

Tumbled tan stone, possibly sandstone or weathered limestone

Indeterminate; likely quartz-rich sandstone or calcitic limestone

Small gray stone, possibly granite or quartz-rich pebble

Indeterminate; likely a weathered quartz–feldspar rock fragment

Likely polished dark metallic mineral specimen

Indeterminate from image; possibly hematite, magnetite, or galena

Likely dark rounded stone or mineral fragment

Indeterminate; possibly a water-worn mafic rock such as basalt

Fossilized tooth, likely a mammalian tooth fragment

Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth

Likely weathered quartz-rich stone

Indeterminate; possibly quartz-bearing granite or milky quartz

Weathered dark rock fragment

Indeterminate; possibly basalt or iron-rich volcanic rock

Small rounded pebble, likely quartz-rich river stone

Indeterminate; likely quartz/chert-bearing lithic clast

Fossil shell fragment, likely brachiopod or bivalve

Indeterminate fossilized carbonate shell; possibly Spiriferida (brachiopod)

Rounded gray pebble

Indeterminate; likely a water-worn silicate or carbonate pebble

Greenish translucent mineral fragment

Indeterminate; possibly serpentine, epidote, or green glassy feldspar