Mineral, Sediment

Iron-rich concretion or slag-like mineral fragment

Likely limonite/goethite (FeO(OH)·nH₂O), possibly magnetite-bearing material

Likely weathered chert or siliceous shale

Cryptocrystalline quartz (SiO₂), possibly with clay minerals

Iron-oxide-cemented sandstone concretion

Ferruginous sandstone concretion, composed mainly of quartz (SiO₂) grains cemented by iron oxides

Sandstone concretion

Arenite sedimentary rock (concretion/nodule)

Banded Sandstone

Clastic Sedimentary Sandstone

Concretion

Calcareous or ferruginous concretion

Orbicular jasper

Silicified volcanic or sedimentary rock, primarily microcrystalline quartz (SiO₂) with iron-oxide-rich orbicules

Concretion

Sedimentary Concretion (e.g., Siderite or Ironstone)

Small rounded mineral pebble, possibly feldspar or quartz

Uncertain from image; likely a quartz- or feldspar-rich grain

Bumblebee Jasper (technically a type of Agate/Anhydrite)

Calcite and Anhydrite with inclusions of Realgar and Orpiment (As2S3)

Rounded quartz-rich pebble, possibly milky quartz

Quartz (SiO₂), provisional identification

Sandstone (Quartzose)

Arenite (primarily SiO2)

Ammonite fossil

Ammonoidea (likely an involute ammonite; exact genus requires preparation and context)

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

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

Weathered iron-rich concretion or ironstone pebble

Goethite/hematite-bearing limonite concretion (approximate identification)

Banded Sandstone (River Pebble)

Clastic Sedimentary Rock (primarily Quartzite and Feldspar grains)

Fossil Shark Teeth (likely Sand Tiger Shark)

Carcharias taurus (fossilized dentition)

Ironstone concretion (possible limonite/goethite-rich piece)

Iron-oxide-rich ironstone; commonly composed of goethite (FeO(OH)) and/or limonite

Likely ironstone or iron-rich sandstone fragment

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

Worn granitic or quartz-rich rock fragment

Likely granite or granitic gneiss; exact identification requires a fresh surface and testing

Possible iron-rich concretion or weathered ironstone

Goethite/hematite-bearing limonite concretion (tentative)

Sandstone (River Pebble)

Arenite

Rounded river pebble

Indeterminate; likely quartz-rich sandstone, chert, or weathered volcanic rock

Milky quartz

Quartz (SiO₂), likely massive or microcrystalline quartz

Petrified Wood

Silicified Wood (mainly Quartz / SiO2)

Shale

Argillite / Shaly Mudstone

Tumbled reddish sandstone pebble

Quartz-rich sandstone, likely ferruginous arkose or quartz arenite

Fossil Shark Tooth

Elasmobranchii tooth fossil (e.g., Otodus / Carcharocles)

Tumbled jasper or iron-rich chert

Microcrystalline quartz (SiO₂), likely colored by iron oxides

Ironstone Concretion

Siderite or Hematite Concretion

Ironstone Concretion

Siderite or Hematite-rich Concretion (FeCO3 / Fe2O3)

Ironstone Concretion

Goethite-rich Siltstone / Siderite (FeCO3)

Conglomerate

Conglomerate

Sandstone Concretion

Sandstone (Sedimentary Rock) with silica or calcite cement

Sandstone Concretion

Septarian Concretion (Nodule)

Rounded pebble, likely greenstone or altered basalt

Likely chlorite- or epidote-altered basalt; identification is uncertain from the image alone

Stream-Rounded Shale or Mudstone

Argillaceous sedimentary rock

Mica schist

Schist dominated by muscovite/biotite mica, commonly with quartz and feldspar

Petrified Wood

Silicified Wood (Permineralized wood)

Petrified Wood

Silicified Wood (SiO2)

Small tumbled dark stone, possibly sodalite or blue-gray jasper

Undetermined from the image; visual appearance is consistent with sodalite-bearing rock or jasper

Quartz Grain

Silicon Dioxide (SiO2)