Indeterminate

Fossilized bone or tooth fragment in rock matrix

Indeterminate vertebrate fossil; mineralized apatite (carbonate-fluorapatite) with silica/carbonate-rich matrix

Rounded river pebble, probably quartz-rich sandstone

Indeterminate lithic clast; likely fine-grained quartz–feldspar sandstone or weathered quartzite

Iron-stained quartz-rich rock, possibly weathered granite or quartzite

Indeterminate quartz–feldspar aggregate with iron-oxide staining; likely granitic or hydrothermal material

Weathered quartz-rich rock, possibly granite or gneiss

Indeterminate granitic rock; likely quartz (SiO₂) with feldspar and mica/iron-oxide minerals

Likely weathered pebble or mineral fragment

Indeterminate; possibly quartz-rich stone, iron-stained feldspar, or a small chert fragment

Weathered quartz-bearing rock, possibly granite or gneiss

Indeterminate felsic silicate rock; likely quartz (SiO₂) with feldspar and dark mica/amphibole

Manufactured stone veneer wall

Likely cut limestone or sandstone masonry blocks; exact lithology is indeterminate from the image

Weathered fossil shell fragment

Indeterminate bioclastic carbonate, likely molluscan shell (calcium carbonate, commonly aragonite or calcite)

Rounded brown pebble, likely weathered basalt or iron-rich volcanic rock

Indeterminate fine-grained mafic rock; possible basalt (plagioclase–pyroxene ± iron oxides)

Small rounded pebble, likely limestone or quartz-rich sedimentary fragment

Indeterminate lithic clast; probable micritic limestone (CaCO₃) or weathered quartz-rich stone

Weathered river cobble, possibly sandstone or volcanic tuff

Indeterminate lithology; likely fine-grained sandstone/siltstone, with possible iron-oxide veining

Water-worn brown stone, likely basalt or chert

Indeterminate; possible fine-grained basalt (plagioclase–pyroxene) or ferruginous chert (microcrystalline SiO₂)

Weathered iron-rich stone, possibly sandstone or ironstone

Indeterminate; likely quartz-rich sandstone with iron-oxide cement, possibly hematite/goethite

Unidentified light-colored rock or mineral specimen

Indeterminate; possibly weathered calcite-rich material, limestone, or pale quartz-bearing rock

Small brown pebble or mineral fragment

Indeterminate from image; possibly iron-stained quartz, ironstone, or a dark mineral grain

Polished dark breccia or gneiss-like rock

Indeterminate polymictic breccia; likely quartz–feldspar–mica rock with iron-oxide staining

Rounded river pebble, likely quartz-rich sandstone or quartzite

Indeterminate; probable quartz (SiO₂) with feldspar, iron-oxide staining, and minor lithic grains

Iron-rich river pebble (likely weathered basalt or ironstone)

Indeterminate; possibly ferruginous basalt, hematite-rich ironstone, or limonite-coated mafic rock

Polished dark stone fragment, possibly slate or schist

Fine-grained foliated metamorphic rock; exact mineral composition is indeterminate from the image

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

Indeterminate siliciclastic pebble; likely quartz–feldspar sandstone, with possible iron-oxide staining

Rounded river cobble, likely weathered volcanic or metamorphic rock

Indeterminate from photograph; possible basaltic-andesite, rhyolite, or quartz-rich metamorphic lithology

Fossiliferous limestone pebble (probable coral or shell fossil)

Calcite (CaCO₃), commonly biogenic limestone; exact fossil taxon indeterminate from the image

Likely weathered iron-rich pebble (brown sandstone or ironstone)

Indeterminate ferruginous sandstone/ironstone; commonly quartz (SiO₂) with iron oxides such as goethite and hematite

Polished river pebble

Indeterminate; likely fine-grained quartz-rich sedimentary rock or weathered volcanic rock

Uncertain small polished gemstone or mineral

Indeterminate; likely quartz-family material, possibly druzy quartz or glass-like chalcedony

Weathered gray stone, possibly basalt or granitic rock

Indeterminate fine- to medium-grained silicate rock; possible basalt, diabase, or weathered granite

Reddish-brown crystalline rock, possibly weathered granite or garnet-bearing schist

Indeterminate; likely quartz–feldspar–mica rock with iron oxides, potentially garnet-bearing

Unidentified polished stone fragments

Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock

Weathered quartz-bearing rock fragment

Indeterminate; likely quartz-rich granite or silicified host rock with iron-oxide staining

Fossil plant impression, likely fern or leaf

Indeterminate fossilized vascular-plant compression; possibly a fern frond or other Paleozoic plant

Rounded river pebble, likely quartz-rich sandstone or fine-grained quartzite

Indeterminate quartz-rich lithic clast; likely quartz sandstone (SiO₂-rich) or quartzite

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Small seashell fossil or shell fragment

Likely calcium-carbonate shell material, chiefly aragonite or calcite; exact species indeterminate

Weathered quartz-bearing rock, possibly rhyolite or granite

Indeterminate felsic igneous rock; likely quartz–feldspar aggregate with iron-oxide staining

Rounded greenish-gold rock or mineral pebble

Indeterminate; possibly serpentine-rich stone, weathered sulfide, or iron-stained metamorphic rock

Unidentified dark mineral or rock specimen

Indeterminate from the severely blurred image; possible dark igneous rock or opaque mineral

Small polished or naturally worn stone, possibly quartz-bearing rock

Indeterminate from the blurred image; likely quartz (SiO₂) or a pale feldspar-rich fragment

Rounded gray pebble, likely quartz-rich sandstone or chert

Indeterminate lithic clast; possibly quartz arenite (quartz sandstone) or microcrystalline quartz (chert)

Tumbled dark stone, possibly chert or basalt

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)

Likely weathered sandstone or iron-rich chert fragment

Indeterminate; probable quartz-rich sandstone (SiO₂) with iron-oxide cement, possibly chert

Rounded weathered pebble, likely sandstone or altered limestone

Indeterminate clastic carbonate/siliciclastic rock; exact identification requires a fresh surface and tests

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil cockle or clam shell, aragonite/calcite replaced or preserved