Indeterminate

Weathered sedimentary rock, possibly sandstone

Indeterminate clastic sediment; probable quartz-rich sandstone

Weathered brown rock fragment

Indeterminate; possibly iron-stained sandstone or weathered limestone

Small gray metallic-looking rock

Indeterminate; possibly galena-bearing ore or metallic sulfide

Likely tumbled brown mineral fragment

Indeterminate; possibly iron-stained quartz, jasper, or carnelian

Unidentified metallic mineral fragment

Indeterminate; possibly galena, hematite, or a metallic meteorite fragment

Orbicular/porphyritic stone, likely weathered igneous rock

Indeterminate; possibly orbicular granite or a weathered felsic porphyry

Tumbled blue-gray stone, likely marble or quartzite

Indeterminate; probably calcite marble (CaCO₃) or quartzite (SiO₂)

Tumbled brown stone, possibly chert or iron-stained quartzite

Indeterminate from photograph; possible microcrystalline quartz (SiO₂)

Polished dark river pebble

Indeterminate; likely basalt or fine-grained mafic rock

Fossil coral or shell fragment

Indeterminate calcareous fossil; likely aragonite or calcite (CaCO₃)

Likely weathered quartz-bearing rock fragment

Indeterminate; possibly granitic or metamorphic quartz–feldspar aggregate

Weathered iron-rich rock fragment

Indeterminate; likely limonite/goethite-bearing sandstone or laterite

Rounded weathered stone, likely sandstone or iron-stained quartzite

Indeterminate; probable quartz-rich sandstone (SiO₂-dominant)

Brecciated polymictic rock, possibly impact breccia

Polymictic breccia; exact lithology indeterminate from image

Tooth fossil, likely mammalian or reptilian fragment

Indeterminate fossilized tooth; enamel and dentine, taxon unresolved

Weathered rounded cobble

Indeterminate lithology; likely weathered sandstone or volcanic rock

Dark gray rock fragment (tentative basalt or slate)

Indeterminate; possibly fine-grained basalt, or metamorphic slate

Likely polished/tumbled fossil shell or concretion

Indeterminate; possibly a fossil bivalve or gastropod in mineralized matrix

Unidentified small rock fragments

Indeterminate from image; possibly quartz-rich material

Dark gray crystalline rock, possibly mica-rich schist or graphite-bearing gneiss

Indeterminate; likely quartz–feldspar–mica metamorphic rock

Fine-grained gray stone, likely slate or weathered basalt

Indeterminate; possible slate (foliated phyllite-grade shale)

Weathered quartz-rich rock fragment

Indeterminate; likely altered granite or quartz-bearing pegmatite

Tumbled brown pebble

Indeterminate; possibly weathered basalt or iron-stained quartzite

Fossil-bearing sandstone or mudstone

Indeterminate sedimentary matrix with a possible bivalve or shell fossil

Fossil brachiopod or bivalve shell

Indeterminate fossilized carbonate shell; possibly a brachiopod (Brachiopoda)

Likely fossil shell fragment

Indeterminate mollusk fossil; possibly a gastropod or bivalve in limestone

Unidentified weathered rock fragment

Indeterminate; possibly vesicular basalt or weathered volcanic rock

Likely tumbled pale-green mineral specimen

Indeterminate; possibly serpentine, calcite, or pale jade/nephrite

Light-colored pebble, likely quartzite or weathered limestone

Indeterminate from image; possible quartzite (microcrystalline SiO₂)

Weathered brown rock fragment

Indeterminate; possibly ferruginous sandstone or weathered volcanic rock

Weathered brown rock fragment (likely sandstone or iron-stained quartzite)

Indeterminate; probable quartz-rich sandstone, SiO₂-dominated

Fossil bone, possibly a large mammal long-bone fragment

Fossilized cortical bone; taxon indeterminate from the photograph

Rounded quartz-rich pebble, possibly granite or gneiss

Indeterminate granitoid; likely quartz–feldspar–biotite aggregate

Possible dark igneous rock

Indeterminate; likely basalt or fine-grained mafic rock

Tiny amber-colored crystal fragment

Indeterminate; possibly quartz, feldspar, mica, or a sulfide mineral

Uncertain small pale mineral fragment

Indeterminate; possibly calcite or a light-colored feldspar fragment

Uncertain small metallic-looking mineral/rock fragment

Indeterminate; possibly galena-bearing rock or metallic slag

Weathered quartz-rich rock, possibly granite or granitic pegmatite

Indeterminate quartz–feldspar aggregate; likely granite/pegmatite

Fossilized bivalve or brachiopod shell

Indeterminate calcitic shell fossil; likely Bivalvia or Brachiopoda

Fossilized tooth or tooth fragment

Indeterminate vertebrate tooth; likely mammalian, mineralized hydroxyapatite

Likely fossilized shell or carbonate concretion

Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)

Weathered sandstone or quartz-rich sedimentary pebble

Indeterminate lithic fragment; likely quartz arenite (sandstone)