Rock (Likely Sedimentary)

Ironstone (likely Ferruginous Siltstone/Sandstone)

Ferruginous sedimentary rock (FeOx-rich clastic)

Small pale stone, possibly limestone

Unidentified carbonate rock; calcite-rich limestone is one possibility

Sandstone with Trace Fossils

Arenite / Quartzwacke with Ichnofossils

Fossiliferous limestone

Bioclastic calcarenite/calcirudite, chiefly calcite (CaCO₃)

Sandstone (with biological crust)

Arenite (SiO2 based)

Weathered quartz-rich pebble

Likely quartz aggregate, SiO₂, possibly quartzite or silicified rock

Quartz-rich gneiss

Foliated quartz–feldspar–mica gneiss, possibly migmatitic

Weathered quartz-rich rock, possibly quartzite or altered granite

Quartz-dominant silicate rock; exact identification requires a fresh surface and tests

Weathered iron-rich rock, likely hematite-bearing sandstone or ironstone

Hematite/goethite-bearing ferruginous sandstone or ironstone; exact identification requires testing

Weathered gray sandstone or siltstone cobble

Clastic sedimentary rock, likely quartz-rich sandstone/siltstone (diagnosis uncertain from image)

Chalcedony (Agate/Carnelian precursor)

Chalcedony (Silicon Dioxide, SiO2)

Sandstone cobble

Quartz-rich sandstone, likely arkose or lithic sandstone

Likely weathered sandstone fragment

Quartz-rich sandstone, predominantly SiO₂ with minor feldspar and iron-oxide cement

Pyrite-bearing metamorphic rock (likely pyrite schist or quartz–pyrite ore)

Pyrite (FeS₂) in a quartz–mica-rich matrix; exact host rock is uncertain from the image

Weathered granite or granitic gneiss pebble

Granite; primarily quartz, feldspar, and mica (exact identification is uncertain from the image)

Rounded gray pebble (likely fine-grained volcanic or sedimentary rock)

Undetermined from image; possibly andesite or a fine-grained sandstone

Granitic Gneiss

Gneiss (containing Potassium Feldspar and Quartz)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Chert (specifically Jasper)

Silicon dioxide (SiO2) with iron oxide inclusions

Rounded granitic cobble

Granite, likely biotite granite or granodiorite

Weathered metallic sulfide-bearing rock, possibly pyrite-rich ore

Tentatively pyrite (FeS₂) with iron oxides and host rock; exact identification requires testing

Glacially rounded metamorphic boulder

Likely foliated amphibolite or gneiss; exact identification requires a fresh surface and mineral examination

Quartz vein fragment

Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions

River Pebble (likely Quartzite or Chert)

Sedimentary Clast (Silicon Dioxide dominant)

Rounded river pebble, likely weathered sandstone or volcanic rock

Indeterminate fine-grained lithic clast; possible sandstone (quartz-rich)

Rounded volcanic pebble

Likely basaltic-andesite or altered basalt; exact identification requires testing

Rounded sandstone pebble

Quartz-rich sandstone, likely arkose or lithic sandstone

Blue-gray chalcedony or quartz-rich rock

Microcrystalline quartz, SiO₂; possibly silicified host rock

Mixed landscaping gravel and rounded fieldstones

Lithologically mixed aggregate; likely quartzite, basalt, granite, and weathered sedimentary rocks

Weathered pegmatitic granite

Granite/pegmatite, chiefly quartz (SiO₂), feldspar, and mica

Conglomerate (likely polymictic conglomerate)

Clastic sedimentary rock composed of rounded lithic and mineral clasts in a finer matrix; commonly quartz, feldspar, chert, and volcanic fragments cemented by silica, calcite, or iron oxides

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Rounded pebble, likely quartz-rich river stone

Indeterminate; possibly quartzite, chert, or a weathered quartz-feldspar rock

Rounded white pebble, likely quartz-rich rock

Most consistent with quartzite or milky-quartz pebble; exact identification requires testing

Sandstone (with potentially metamorphic or basaltic bands)

Arenite / Lithic Wacke

Weathered dark volcanic rock, likely basalt

Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, commonly with olivine

Weathered sandstone pebble

Quartz-rich sandstone, likely ferruginous sandstone

Weathered pale-blue rock fragment

Unidentified; the image does not show enough detail for a reliable geological identification

Fossiliferous Limestone

Carbonate Rock (CaCO3 with organic inclusions)

Banded Sandstone

Clastic Sedimentary Rock (Quartz Arenite)

Weathered iron-rich rock, possibly laterite or limonite-bearing sandstone

Laterite/ironstone; mainly hydrated iron oxides such as limonite/goethite (FeO(OH)·nH₂O), with possible quartz and clay minerals

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone