Indeterminate

Rounded gray-brown river cobble

Indeterminate lithology; possibly weathered quartzite, chert, or fine-grained sandstone

Small brown-gray mineral fragment

Indeterminate; possibly weathered quartz-, feldspar-, or iron-oxide-bearing rock

Weathered quartz-rich sandstone or granitic rock

Indeterminate; likely iron-stained quartz sandstone, possibly weathered granite

Rounded brown-gray stone, possibly weathered conglomerate or sandstone

Indeterminate clastic sedimentary rock; likely poorly cemented sandstone/conglomerate

Small rounded pebble (rock type indeterminate)

Unidentified lithic pebble; specific composition cannot be determined from the image

Fossil shell

Likely a fossilized marine bivalve shell; exact taxon is indeterminate from the image.

Unidentified tan-gray stone

Indeterminate from the blurry image; it may be a common silicate rock such as quartzite or granite.

Likely green aventurine or serpentine-bearing stone

Indeterminate from image; possibly quartzite with fuchsite mica or serpentinized ultramafic rock

Fossilized shell or coral fragment

Indeterminate marine invertebrate fossil; possibly a worn brachiopod, bivalve, or solitary coral

Small dark mineral specimen, possibly hematite or magnetite

Indeterminate from the image; possible hematite (Fe₂O₃) or magnetite (Fe₃O₄)

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

Indeterminate lithic clast; probable quartz–feldspar aggregate with iron-oxide staining

Likely dark mineral or rock fragment

Indeterminate from image; possibly a dark silicate mineral such as hornblende, biotite, or basalt

Likely polished green cabochon

Indeterminate from image; possibly green aventurine, chrysoprase, jade, or dyed chalcedony

Banded gneiss pebble

Gneiss, chiefly quartz–feldspar–mica; exact variety indeterminate from image

Dark blue polished stone pendant

Indeterminate; possibly sodalite, lapis lazuli, or blue slag/glass-like material

Unidentified gravel and stone fragments

Mixed, indeterminate lithologies; likely quartz, feldspar, and weathered silicate rock fragments

Weathered river pebble, likely quartz-rich sandstone or quartzite

Indeterminate; probable quartz (SiO₂)-rich sandstone/quartzite with iron-oxide staining

Blue glassy gemstone-like specimen

Indeterminate; possibly dyed or treated turquoise, blue apatite, or man-made glass

Dark gray rock fragment

Indeterminate from image; possibly weathered basalt or fine-grained metamorphic rock

Rounded sedimentary pebble, likely limestone or calcareous sandstone

Indeterminate carbonate-rich clastic rock; possibly micritic limestone (predominantly CaCO₃)

Weathered quartz-bearing rock, possibly granite or granitic pegmatite

Indeterminate quartz–feldspar rock; exact identification requires a closer image or testing

Perforated beach pebble (likely sandstone or chert)

Indeterminate siliciclastic sedimentary rock; predominantly quartz (SiO₂), possibly calcareous cement

Fossilized coral or bryozoan fragment

Indeterminate colonial coral/bryozoan fossil; likely calcitic calcium carbonate (CaCO₃)

Light-gray river pebble

Indeterminate; likely fine-grained quartz-rich rock such as quartzite or pale granite

Tumbled cream-colored stone, likely quartz or calcite

Indeterminate from photograph; possibilities include microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Polished black stone, possibly obsidian or black jasper

Indeterminate; likely volcanic glass (obsidian, SiO₂) or microcrystalline quartz (jasper, SiO₂)

Likely weathered sandstone or iron-rich volcanic rock

Indeterminate from photograph; probable ferruginous sandstone, possibly altered volcanic rock

Weathered volcanic rock fragment

Indeterminate fine-grained mafic-to-intermediate igneous rock; possibly andesite or basalt

Small pale stone, possibly quartz or limestone

Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Weathered quartz-rich pebble, possibly sandstone

Indeterminate quartz-rich clastic rock; likely ferruginous sandstone or weathered quartzite

Tumbled brown mineral/rock specimen

Indeterminate from image; likely brown jasper, chert, or iron-stained quartzite

Fossilized bone or bone fragment

Indeterminate fossil bone; mineralized apatite (hydroxyapatite), commonly Ca₅(PO₄)₃(OH)

Rounded river cobble, likely quartz-rich sandstone or quartzite

Indeterminate; probable quartz arenite (sandstone) or low-grade quartzite, chiefly SiO₂

Tumbled brown-black stone, likely smoky quartz or iron-stained agate

Indeterminate from image; possible quartz (SiO₂), chalcedony, or iron-rich jasper

Tiny amber-colored crystal or mineral fragment

Indeterminate from image; possibly quartz, citrine, topaz, or iron-stained feldspar

Fossilized bivalve shell or shell-rich limestone

Likely an indeterminate fossil mollusk; calcite/aragonite (CaCO₃), possibly preserved in limestone

Ammonite fossil

Fossilized ammonoid cephalopod; likely an involute ammonite, exact genus/species indeterminate

Rounded brown river pebble

Indeterminate lithic clast; possibly weathered sandstone or fine-grained volcanic rock

Small weathered stone, likely sandstone or limestone fragment

Indeterminate clastic or carbonate rock; mineral composition cannot be confirmed from the image

Polished fossil shell fragment

Likely fossilized bivalve shell; mineralized aragonite/calcite (exact taxon indeterminate)

Rounded weathered stone, likely quartz-rich sandstone or iron-stained quartzite

Indeterminate; probable quartz (SiO₂)-rich clastic rock with iron-oxide staining

Tumbled stone, likely ocean jasper or quartzite

Indeterminate from photograph; probable quartz-rich silicate rock, mainly SiO₂