Rock (Likely Sedimentary)

Fossil Shell

Invertebrate fossil (Mollusca)

Vesicular basalt (likely weathered volcanic rock)

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Quartzite River Pebble

Quartzite (SiO2)

Weathered sandstone or tuff fragment

Likely quartz-rich sandstone (SiO₂) or porous volcanic tuff; exact identification requires testing

Likely basalt or scoria fragment

Dark mafic volcanic rock, most likely basalt (plagioclase–pyroxene–olivine) or vesicular scoria

Pink granite pebble

Granite, chiefly quartz, feldspar, and mica

Weathered greenstone (likely serpentinite or altered basalt)

Serpentinite-group rock, commonly dominated by serpentine minerals (antigorite/lizardite); exact identification requires testing

Quartz (Smoky/Milky Variety)

Silicon Dioxide (SiO2)

Quartz pebble with host matrix

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with mica or feldspar

Emerald with Matrix (Emerald in Mica Schist)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Likely weathered iron-rich stone

Uncertain; possibly limonite/goethite-bearing rock

Pegmatitic granite (likely feldspar–quartz–mica rock)

Granitic pegmatite; chiefly K-feldspar and quartz, with mica and iron-oxide staining

Granitoid (Granite/Diorite)

Course-grained Plutonic Igneous Rock

Granite

Felsic Plutonic Rock (primarily SiO2)

Basalt

Extrusive mafic igneous rock

Sedimentary Rock Fragments

Clastic Sedimentary Rock

Pumice and Scoria

Vesicular Volcanic Ejecta (Rhyolite/Andesite/Basalt)

Banded River Rock / Gneiss (highly weathered)

Gneiss

White Quartz Pebble

Silicon Dioxide (SiO2)

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2)

Dark metamorphic rock, likely hornfels or fine-grained basalt

Probable hornfels; commonly quartz–feldspar–mica with variable amphibole/pyroxene

Basalt Pebble

Basalt

Weathered quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly iron-oxide stained

Sedimentary Rock (Limestone or Siltstone pebble)

Sedimentary rock fragment

Quartz Pebble (with Mica or Iron staining)

Silicon Dioxide (SiO2)

Honey calcite (calcite-rich limestone/marble fragment)

Calcite — CaCO₃; likely coarse crystalline calcitic rock

Granite Pebble

Granite (Felsic Plutonic Rock)

Granite (River Pebble)

Phaneritic Felsic Igneous Rock

Granite

Phaneritic Igneous Rock (Granite)

Granite Pebble (Weathered)

Phaneritic Felsic Igneous Rock

Granite Cobble

Felsic intrusive igneous rock

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Basalt with Red Inclusions

Aphanitic Mafic Igneous Rock (likely Basalt)

Basalt

Mafic Igneous Pebble

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3)

Tumbled cream-colored stone, likely quartzite or limestone

Probably quartzite (microcrystalline SiO₂); limestone alternative: calcite (CaCO₃)

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (likely a clear or rock crystal variety)

Quartz (SiO2 - Silicon Dioxide)