Mineral, Sediment

Likely quartz-rich rock fragment

Quartz (silicon dioxide, SiO₂), possibly in a granitic or pegmatitic matrix

Likely quartz-rich mineral fragment

Quartz (SiO₂), possibly iron-stained or included quartz

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Ironstone Concretion

Siderite or Hematite Concretion

Mixed gravel and small stones

Unsorted gravel; individual clasts are not identifiable from the image

Concretion

Septarian Concretion

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Ammonite fossil

Fossilized ammonoid cephalopod; likely an ammonite such as Desmoceras or similar Jurassic–Cretaceous form

Sandstone Concretion

Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)

Petrified Wood

Silicified Wood (SiO2 / Quartz pseudomorph after wood)

Petrified Wood

Silicified Wood (SiO2)

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Banded Sandstone or Quartzite Pebble

SiO2 (dominant) with impurities

Fossilized gastropod (snail)

Gastropoda indet.; likely a mineral-replaced or steinkern fossil

White quartz pebbles

Quartz (silicon dioxide, SiO₂), likely milky quartz

Sandstone

Arenite (SiO2 predominantly)

Foliated metamorphic rock, likely biotite gneiss or schist

Biotite-rich gneiss/schist; chiefly quartz, feldspar, and biotite mica

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of cellulose)

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Rounded quartz pebble

Quartz (SiO₂), possibly milky or smoky quartz

Small rounded pebble, possibly quartz-rich stone

Indeterminate from image; likely quartz-bearing silicate rock

Banded ironstone (likely jasper-rich ironstone)

Iron-rich chert/jasper with iron oxides, chiefly hematite and goethite; exact identification requires testing

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Ironstone concretion

Iron-oxide-cemented sediment, commonly goethite (FeO(OH)) and hematite (Fe₂O₃)

Small fossilized tooth, possibly a shark tooth

Indeterminate fossil tooth; species cannot be identified from this image

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Weathered iron-rich concretion or sedimentary rock

Likely ferruginous sandstone or ironstone concretion; exact identification is not possible from the image alone

Gravel

Unconsolidated rock fragments / detrital sediment

Milky quartz pebble

Quartz (SiO₂), likely massive or microcrystalline quartz

Probable fossil tooth fragment

Indeterminate fossilized vertebrate tooth; species cannot be identified from this image

Weathered granitic cobble

Granite, composed mainly of quartz, feldspar, and mica/amphibole

Banded gneiss

Quartz–feldspar–mica gneiss

Petrified Wood

Silicified Wood (Silicon Dioxide - SiO2)

Waterworn pebble, possibly iron-rich basalt or river stone

Unidentified lithic clast; composition cannot be determined reliably from the image

Glauconitic Sandstone

Greensand (Glauconite-bearing sandstone)

Fossil bone, possibly a vertebra

Fossilized vertebrate bone; exact taxon cannot be determined from the image

Petrified Wood

Silicified Wood (SiO2)