Mineral, Sediment

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Coquina or Fossiliferous Sandstone

Fossiliferous Calcarenite (CaCO3 with SiO2 inclusions)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Sedimentary Rock

Sedimentary Rock with Quartz/Feldspar Vein

Ironstone concretion

Iron-oxide-cemented sedimentary concretion, commonly hematite/goethite with quartz or clay

Ironstone concretion

Iron-oxide-cemented sedimentary concretion, commonly composed of goethite and/or hematite with quartz or clay

Gravel and Sediment Sample

Mixed clastic sediment

Likely ironstone pebble

Iron-oxide-rich concretion, composed mainly of goethite and/or hematite

Bivalve seashell (likely cockle or ark clam)

Calcareous shell composed chiefly of aragonite (CaCO₃); exact species cannot be determined confidently from the image

Ironstone concretion (possibly pyrite-bearing)

Iron-rich sedimentary concretion, likely composed of goethite/limonite with possible pyrite

Fossil bivalve shell

Likely an internal mold or mineralized shell of a brachiopod or small bivalve; exact taxonomy requires locality and diagnostic details

Brown stone, likely a weathered chert or iron-stained rock

Unidentified brown lithic specimen; composition cannot be determined from the image

Polished basalt pebble

Basalt, a fine-grained mafic volcanic rock; likely containing plagioclase, clinopyroxene, and iron-magnesium minerals

Quartz Sand/Gravel

Silicon Dioxide (SiO2)

Concretion

Siderite or Ironstone Concretion

Ironstone concretion (possibly a pyrite-bearing concretion)

Iron-oxide-cemented sedimentary concretion; exact mineral composition cannot be confirmed from the photograph

Petrified Wood

Silicified Wood (SiO2)

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Common Pebble / Sedimentary Rock Fragment

Lithified clastic sediment

Coarse sand with a small pebble

Unconsolidated siliciclastic sediment, chiefly quartz and rock fragments

River Pebble

Lithified clastic sediment

Coarse Sand or Fine Gravel

Clastic Sediment (unconsolidated)

Likely iron-rich concretion or weathered ironstone

Ironstone concretion, composed mainly of iron oxides/hydroxides (goethite and/or limonite) cementing sediment

Tumbled beige stone, possibly jasper or limestone

Indeterminate; likely microcrystalline quartz (jasper) or calcium-carbonate limestone

Layered sandstone and shale outcrop

Clastic sedimentary strata, likely sandstone interbedded with mudstone/shale

Small conical fossil shell fragment

Indeterminate gastropod or scaphopod shell; likely calcium carbonate (aragonite/calcite)

Petrified Wood (Jet or Coalified Wood appearance)

Silicified wood (principally SiO2) or Carbonized Wood

Small rounded pebble, likely porous volcanic rock

Possibly vesicular basalt or scoria; exact identification is not possible from the image alone

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Fossilized Shark Tooth

Chondrichthyes tooth

Mammoth fossil footprints and track-bearing sediment

Proboscidean ichnofossil preserved in Pleistocene sediment; likely Mammuthus footprints

Sandstone Concretion

Ferruginous Sandstone Concretion

Petrified Wood / Fossilized Wood

Silicified Wood (Silicon Dioxide - SiO2)

Small rounded pebble (rock type indeterminate)

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

Fossil brachiopod shell

Brachiopoda; exact genus and species cannot be determined from the image

Petrified Wood

Silicified Wood (SiO2)

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Petrified Wood

Silicified Wood (SiO2)

Light-colored rounded stone, possibly quartzite or limestone

Uncertain; likely quartzite (quartz, SiO₂) or calcitic limestone (calcite, CaCO₃)

Likely ironstone concretion

Iron-oxide-cemented sedimentary concretion, commonly hematite/goethite-rich

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)