Rock (Likely Sedimentary)

Sandstone (Greywacke/Siltstone variant)

Clastic Sedimentary Rock (Lithic Wacke)

Bivalve Fossil (Clam)

Class Bivalvia, likely Mercenaria or similar genus

Chert (Agatized)

Silicon Dioxide (SiO2)

Banded Agate

Silicon dioxide (SiO2) - variety of Chalcedony

Rounded gray pebble

Uncertain; likely quartz-rich sandstone, quartzite, or graywacke

Brown quartz-rich pebble (likely chert or weathered quartzite)

Quartz (SiO₂), possibly microcrystalline quartz/chert or quartzite

Quartz (Grain)

Silicon Dioxide (SiO2)

Banded metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly amphibolite-bearing

Weathered sandstone or iron-stained sedimentary rock

Likely quartz-rich sandstone (SiO₂) with iron-oxide staining; exact identification requires testing

Sandstone Pebble

Arenite (primarily SiO2)

Mixed river stones; foreground likely sandstone

Quartz-rich sandstone, with associated rounded quartzite/chert and other cobbles

Weathered metamorphic rock, likely gneiss or schist

Indeterminate foliated silicate rock; commonly quartz–feldspar–mica assemblage

Likely pink-orange halite (rock salt)

Halite (NaCl); identification is provisional from the photograph

Weathered gray rock fragment

Tentatively shale or fine-grained sandstone; exact identification requires testing

Rounded river pebble, likely quartz-rich sandstone or weathered igneous rock

Indeterminate; possibly quartzite, sandstone, or fine-grained granitic rock

Sandstone

Arenite (primarily Quartz Arenite)

Jasper / Chert (River Rock)

Microcrystalline Quartz (SiO2)

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony

Quartz Druze (Crystalline Quartz)

Silicon Dioxide (SiO2)

Basalt or Siltstone Pebbles

Mafic volcanic rock (Basalt) or Indurated Siltstone

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Dark, mica-rich metamorphic rock (possibly schist)

Mica schist, tentatively; exact identification is limited by the small, partly obscured specimen

Pink Chalcedony (Agate/Jasper blend)

Silicon Dioxide (SiO₂)

Chert (Common Opal/Jasper variety)

Microcrystalline Quartz (SiO2) with hydration

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Sandstone (lithic wake or graywacke)

Clastic sedimentary rock (primarily quartz and lithic fragments)

Sandstone

Clastic sedimentary rock (primarily Quartz and Feldspar)

Weathered granite-like pebble

Granite or granitic gneiss; mainly quartz, feldspar, and mica

Iron-rich sandstone concretion

Ferruginous sandstone, cemented chiefly by iron oxides (such as goethite and hematite)

Sandstone (likely Arkosic or Lithic Sandstone)

Arenite (composed primarily of SiO2 with various lithic fragments)

Banded gneiss (likely weathered paragneiss)

Gneiss; quartz–feldspar–mica ± amphibole assemblage

Sandstone with Iron Oxide

Arenite (SiO2 with Fe2O3 inclusions)

Sandstone

Arenite (SiO2 based with quartz grains)

Likely weathered gneiss

Foliated metamorphic rock, commonly quartz–feldspar–mica gneiss

Weathered gray sandstone or siltstone

Clastic sedimentary rock, likely quartz–feldspar-rich sandstone/siltstone

Fossiliferous Siltstone

Clastic Sedimentary Rock with Fossil Inclusions

Likely ironstone concretion

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

Quartz-veined metamorphic rock, likely mica schist

Mica schist with a milky-quartz vein; predominantly quartz, feldspar, and biotite/muscovite mica

Weathered sandstone pebble

Quartz-rich sandstone, commonly arkose or lithic sandstone

Limitation Concretion

Ironstone Concretion (Goethite/Limonite)

Weathered iron-rich rock, possibly basalt or ironstone

Uncertain; likely weathered basalt (plagioclase–pyroxene) or hematite/goethite-bearing ironstone