Rock (Likely Sedimentary)

Likely weathered mica schist fragment

Mica schist, chiefly muscovite/biotite mica with quartz and feldspar

Sandstone (Wonderstone)

Clastic Sedimentary Rock (primarily SiO2)

Fossilized Brachiopod

Brachiopoda (Phylum)

Chert or Flint

Silicon dioxide (SiO2)

Fossil Snail

Gastropoda (fossilized)

Claystone Concretion

Septarian Concretion (Ironstone-rich)

Weathered quartz-rich rock fragment

Indeterminate; possibly weathered granite, quartzite, or rhyolite

Tumbled serpentine (likely)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄

Rough Corundum (likely Sapphire/Zircon-bearing)

Aluminium Oxide (Al2O3)

Rounded granitic gneiss or granite cobble

Quartz–feldspar–mica granitoid; possibly weathered gneiss

Basalt (Vesicular/Waterworn)

Basalt (Mafic Extrusive Igneous Rock)

Geode (Quartz / Chalcedony Geode)

SiO2 (Silicon Dioxide)

Quartzite (Yellow/Orange variety)

Quartzite (primarily SiO2)

Likely basalt (possibly scoriaceous basalt)

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine, with minor iron–titanium oxides

Tumbled jasper (likely ocean or orbicular jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and dark accessory minerals

Sandstone (Quartzose)

Arenite (primarily SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Pebble (with Iron Inclusions)

Silicon Dioxide (SiO2)

Basalt Pebble

Mafic Igneous Rock (Basalt)

Basalt

Basalt (Mafic volcanic rock)

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Shale (with Iron Oxide staining)

Fissile Mudstone (primarily Quartz and Clay minerals)

Blue Chalcedony (likely dyed)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Rounded dark-gray pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase ± pyroxene, amphibole, and minor olivine

Quartzite Pebble

Quartzite (composed primarily of SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Orange Calcite (likely polished specimen)

Calcite

Weathered basalt or iron-rich river cobble

Basalt, likely with iron-oxide staining; exact identification requires testing

Sandstone (lithic wacke)

Arenite / Lithic Wacke (mostly SiO2 with rock fragments)

Coal

Combustible sedimentary rock

Sandstone

Clastic Sedimentary Rock

Jasper

Silicon Dioxide (SiO2) with impurities (mostly Iron Oxides)

Sandstone

Arenite

Sandstone

Clastic Sedimentary Rock

Sandstone

Clastic Sedimentary Rock

Fossiliferous Limestone

Biogenic Sedimentary Rock

Sandstone

Clastic Sedimentary Rock

Sandstone

Sedimentary Clastic Rock

Sandstone

Clastic Sedimentary Rock

Sandstone

Clastic Sedimentary Rock

Sandstone

Clastic Sedimentary Rock