Rock (Likely Sedimentary)

Banded river pebble

Likely banded sandstone or siltstone; exact identification requires testing

Pebble or Cobble (likely composed of sandstone or conglomerate)

Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)

Sandstone (likely Quartzose)

Arenite

Sandstone (likely Calcareous or Micaceous)

Clastic sedimentary rock (primarily Quartz with Cementing Agents)

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica gneiss

Small brown quartz-rich pebble, possibly chert or jasper

Microcrystalline quartz (SiO₂), tentative

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Weathered sandstone fragment

Clastic sandstone, composed mainly of quartz and feldspar grains cemented by silica, calcite, or iron oxides

Sandstone (likely Arkosic)

Clastic Sedimentary Rock (primarily SiO2 with Feldspar)

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Sandstone (lithic wacke/arenite)

Clastic sedimentary rock (primarily SiO2)

Likely blue-gray gneiss

Gneiss, a foliated metamorphic rock; exact mineral composition cannot be confirmed from the image

Rounded gray-brown pebble

Indeterminate; likely weathered quartz-rich sandstone or fine-grained volcanic rock

Biotite-bearing granite or granitic gneiss

Quartz–feldspar–biotite granite; possibly weakly foliated granitic gneiss

Weathered sandstone or siltstone cobble

Clastic sedimentary rock, likely quartz–feldspar lithic sandstone (exact identification requires testing)

Sandstone (likely Arkosic)

Arenite (SiO2 with KAlSi3O8)

Sandstone (Quartzose)

Arenite (SiO2 based typically)

Rounded brown river pebble

Indeterminate lithic fragment; possibly weathered sandstone, mudstone, or basalt

Limestone with Lichen

Carbonate Sedimentary Rock (primarily CaCO3)

Sandstone (Weathered Pebble)

Arenite (composed primarily of SiO2)

Polished orbicular stone, likely granite or diorite

Granite–diorite, composed mainly of feldspar, quartz, and dark amphibole/biotite

Sandstone (with Iron Staining)

Arenite (Silicon Dioxide, SiO2, often with iron oxides like Limonite)

Polished green banded stone, likely serpentine or altered greenstone

Probable serpentinite/greenstone; commonly dominated by serpentine-group minerals, chlorite, epidote, or actinolite

Granite

Phaneritic Igneous Rock (Granite)

Banded metamorphic rock, likely gneiss or metasedimentary slate

Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins

Sandstone

Arenite (primarily SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

Polished banded gneiss pebble

Gneiss, chiefly quartz–feldspar–mica; exact mineralogy uncertain from image

Weathered granitic cobble

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

Banded dark pebble (likely gneiss or banded metamorphic rock)

Indeterminate from the image; possibly banded gneiss

Sandstone (likely Quartzose)

Sandstone (Principally SiO2)

Likely weathered sandstone or iron-stained sedimentary pebble

Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone

Sandstone River Cobble

Arenite (SiO2 based)

Chert (Likely Jasper)

Microcrystalline Quartz (SiO2)

Small weathered stone, likely sandstone or limestone fragment

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

Gneiss (Granitic Gneiss)

Gneiss

Fossiliferous Shale

Fossiliferous Mudstone / Shale

Banded gneiss

Quartz–feldspar gneiss, possibly biotite-bearing; exact identification requires testing

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Biotite-rich schist (likely mica schist)

Mica schist; predominantly quartz, biotite mica, and feldspar

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Iron-rich sedimentary rock, likely banded iron formation fragment

Banded iron formation (BIF), composed chiefly of hematite/magnetite and chert