Rock (Likely Sedimentary)

Quartz Pebble

Silicon Dioxide (SiO2)

Fossilized Mosasaur Tooth

Mosasauridae (likely Prognathodon or Mosasaurus)

Polished basalt (likely vesicular basalt)

Basalt; predominantly plagioclase, clinopyroxene, and commonly olivine or iron-titanium oxides

Polished porphyritic basalt (likely)

Basalt, a fine-grained mafic volcanic rock; visible inclusions may be olivine, feldspar, or vesicle infillings

Banded Chert (Jasper) River Pebble

Microcrystalline Quartz (SiO2)

Sandstone with Trace Fossils

Arenite with Ichnofossils

Pyrite-bearing metamorphic rock (probable pyrite schist)

Schist containing pyrite (FeS₂), with probable quartz and mica

Quartz-rich breccia or altered granite fragment

Polymineralic quartz–feldspar rock, likely hydrothermally altered granite/pegmatite

Amazonite

K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)

Quartz-bearing iron-rich rock, possibly quartzite or hydrothermal breccia

Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite; exact host rock is uncertain from the photograph

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Goldstone

Avventurina (Cu + SiO2 glass)

Weathered granite or granitic gneiss pebble

Granite; chiefly quartz, feldspar, and mica

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Granite

Granite (Felsic Intrusive Igneous Rock)

Granite (Core Sample)

Phaneritic Felsic Igneous Rock (Granite)

Granite (River-worn pebble)

Phaneritic plutonic rock (SiO2 + Al2O3)

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Chalcedony (Agate/Chert)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite

Sandstone (Weathered Cobble)

Clastic sedimentary rock (primarily SiO2)

Weathered quartz-rich rock, possibly granite or pegmatite fragment

Uncertain; likely quartz–feldspar aggregate, potentially granitic pegmatite

Schist (Garnet-Mica Schist)

Garnetiferous Mica Schist (primarily Muscovite/Biotite and Almandine Garnet)

Rounded gray pebble, likely basalt or fine-grained volcanic rock

Probable basalt; exact identification is uncertain from the photograph

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Granite

Phaneritic plutonic rock (Quartz, Feldspar, Mica)

Likely weathered quartz-rich stone

Probably quartz-bearing sandstone or milky quartz; exact identification requires testing

Botiroidal Chalcedony or Silicified Fossil Coral

Silicon Dioxide (SiO2) - Chalcedony / Scleractinia (if fossilized)

Chert (Heart-shaped Pebble)

Cryptocrystalline quartz (SiO2)

Orange Calcite (Iron-Stained)

Calcium Carbonate (CaCO3)

Quartz (Tumbled/Water-worn)

Silicon Dioxide (SiO2)

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss

Jasper Quarzite (possibly Lake Superior Agate mix)

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)

Fossiliferous Kalkstein (Marl/Sandstone)

Fossiliferous calcarenite/siltstone

Likely quartz-rich river pebble

Milky quartz or quartz-bearing granitic/gneissic fragment (SiO₂-dominant)

Likely tumbled quartz-rich pebble

Quartz (SiO₂), possibly a weathered quartzite or chalcedony pebble

Biotite-bearing granite or gneiss

Felsic granitoid; chiefly quartz, feldspar, and biotite mica

Quartzite

Quartzite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)