Sedimentary Or Igneous Fragment

Basalt Pebble

Extrusive Igneous Rock

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Limestone (Flagstone)

Fossiliferous Limestone (CaCO3)

Fossiliferous Limestone

Calcium Carbonate (CaCO3)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz / Quartz Geode Fragment

Silicon Dioxide (SiO2)

Chert / Flint Conglomerate

Silicified Sedimentary Breccia (primarily SiO2)

Milky Quartz / Chalcedony

Silicon Dioxide (SiO2)

Vesicular Basalt

Basalt (Mafic Extrusive Igneous Rock)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Biogenic Fossils

Conglomerate

Conglomerate

Silicified Gastropod Fossil (Agatized Fossil)

Gastropoda (Class) preserved in Chalcedony/Quartz (SiO2)

Fossilized Brachiopod Shell / Mold

Phylum Brachiopoda (Fossilized organic matrix replaced by Silica/Calcite)

Sandstone Pebble

Sandstone (primarily SiO2)

Pyrite

Iron Sulfide (FeS2)

Sandstone Pebble

Arenite

Sandstone (Quartzose)

Arenite (primarily SiO2)

Green Fuchsite and Quartz

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Pale green tumbled mineral fragment, likely serpentine or green calcite

Probable serpentine-group mineral (Mg3Si2O5(OH)4) or, less likely, calcite (CaCO3); identification is uncertain from the photograph

Quartz Breccia with Iron Staining

Tectonic or Sedimentary Breccia (SiO2 with Fe2O3)

Vesicular Sandstone

Clastic Sedimentary Rock (Sandstone)

Fossiliferous limestone

Bioclastic limestone, composed mainly of calcite (CaCO₃)

Fossilized Bone (Petrified Bone)

Permineralized Bone Fossil

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite

Limestone with Fossil inclusions

Fossiliferous Limestone (CaCO3)

Sandstone

Arenite (SiO2 primarily)

Weathered limestone or calcareous sandstone

Likely micritic limestone (calcite, CaCO₃), possibly carbonate-rich sandstone

Brecciated Chert with Quartz Veining

Microcrystalline Quartz (SiO2) Breccia

Fossiliferous Limestone

Limestone (CaCO3 with Limonite/Goethite staining)

River Pebble (Granitic / Quartzite Pebble)

Quartz-Feldspar Aggregate (SiO2 / KAlSi3O8)

Basalt Pebble (Beach Pebble)

Mafic Volcanic Rock (Basalt)

Basalt

Basalt (Mafic volcanic rock)

Polymictic breccia, possibly volcanic breccia

Polymictic clastic breccia; likely a matrix-supported breccia containing lithic fragments, quartz, feldspar, and dark mafic minerals

Chert (Flint)

Silicon Dioxide (SiO2)

Chert

Chert (Microcrystalline Quartz, SiO2)

Sandstone

Arenite

Sandstone

Arenite (SiO2 based)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone

Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)