Rock (Likely Sedimentary)

Sandstone (lithic wacke/arenite)

Clastic sedimentary rock (primarily SiO2)

Limestone (specifically Travertine or Tufa)

Calcium Carbonate (CaCO3)

Sandstone (likely Arkosic)

Clastic Sedimentary Rock (primarily SiO2 with Feldspar)

Sandstone (Quartzose)

Arenite (SiO2 based typically)

Likely mica-bearing metamorphic rock (possibly schist)

Mica schist, composed mainly of quartz and mica (muscovite and/or biotite); identification is approximate from the image

Iron-stained sandstone

Quartz-rich sandstone with iron-oxide staining (quartz, SiO₂; hematite/goethite, Fe₂O₃/FeO(OH))

Quartz-rich chalcedony (likely silicified rock)

Microcrystalline quartz, SiO₂; possibly silicified limestone or jasper

Small brown quartz-rich pebble, possibly chert or jasper

Microcrystalline quartz (SiO₂), tentative

Sandstone (likely Quartzose)

Sandstone (Principally SiO2)

Rounded river pebble, likely quartz-rich sandstone or quartzite

Composition and exact rock type cannot be determined from the photo; likely quartz (SiO₂) with minor feldspar and rock fragments

Rounded pebble, likely mixed lithology

Lithology uncertain; possibly a fine-grained metamorphic or volcanic rock with a quartz-rich/pink feldspar vein or inclusion

Rounded brown river pebble

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

Sandstone (likely Arkosic)

Arenite (SiO2 with KAlSi3O8)

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Banded metamorphic rock, likely gneiss

Banded quartzofeldspathic gneiss (probable paragneiss or orthogneiss)

Weathered mafic rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and minor olivine or iron oxides

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Chert (Likely Jasper)

Microcrystalline Quartz (SiO2)

Weathered sandstone fragment

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

Small brown rock fragment, possibly iron-stained quartz or chert

Unidentifiable from the photograph; potentially quartz (SiO₂) or microcrystalline silica (chalcedony/chert)

Sandstone (likely Quartzose type)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Biotite-bearing granite or granitic gneiss

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

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Sandstone (Weathered Pebble)

Arenite (composed primarily of SiO2)

Probable mica schist

Schist, likely muscovite–biotite schist

Likely mica schist

Mica-rich schist, probably muscovite–quartz schist

Weathered sandstone or siltstone cobble

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

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Small pale limestone or calcareous pebble

Likely calcite-rich limestone (primarily CaCO₃); exact identification requires testing

Banded metamorphic rock, likely gneiss or metasedimentary slate

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

Small flint/chert fragment (tentative)

Chert, microcrystalline quartz (SiO₂)

Vesicular Sandstone

Clastic Sedimentary Rock (Sandstone)

Polished orbicular stone, likely granite or diorite

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

Granite

Phaneritic Igneous Rock (Granite)

Milky quartz with iron staining

Quartz, silicon dioxide (SiO₂)

Sandstone (with Iron Staining)

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

Sandstone (likely Arkose or Lithic)

Clastic sedimentary rock (primarily SiO2)

Sandstone (likely Quartzose)

Clastic sedimentary rock (SiO2 primary)

Smooth river pebble

Indeterminate lithology; likely fine-grained quartz-rich sandstone, siltstone, or weathered chert

Banded gneiss

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

Fossiliferous Limestone

Calcareous Sedimentary Rock (CaCO3)