Igneous Or Sedimentary (Water Worn)

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Basalt Cobble

Vesicular Basalt (Mafic Extrusive)

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Pegmatite

Coarse-grained Igneous Rock (Granitic Pegmatite)

Pumice

Pumice (Vitreous volcanic rock)

Chert (Jasper)

Silicon dioxide (SiO2)

Scoria (with likely iron oxidation)

Scoria (Basaltic Scoria)

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Sandstone (Red Arkose)

Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)

Limestone Fragment

Sedimentary rock (primarily Calcium Carbonate, CaCO3)

Conglomerate

Conglomerate (clastic sedimentary rock)

Granitic Pegmatite (Muscovite and Quartz)

Pegmatite (KAl2(AlSi3O10)(OH)2 / SiO2)

Graphic Granite

Graphic Granite (variety of Pegmatite)

Granitic Pegmatite with Schorl

Granitic Pegmatite (Schorl: NaFe3Al6(Si6O18)(BO3)3(OH)3OH)

Granite (weathered cobble)

Granite

Basalt River Cobble

Basalt (Mafic Igneous Rock)

Diorite (weathered)

Intermediate plutonic igneous rock

Basalt (River Pebble)

Extrusive mafic igneous rock

Diorite (River Cobble)

Intermediate plutonic igneous rock

Pumice

Pumice (extrusive volcanic rock)

Shungite

Non-crystalline carbon (high-carbon metamorphic rock)

Glauconite

(K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)

Granite River Rock

Phaneritic Felsic Igneous Rock (Granite)

Granite Pebble

Granite (Phaneritic Acidic Igneous Rock)

Limestone

Sedimentary Calcite (CaCO3)

Aquamarine

Beryl (Be3Al2Si6O18)

Quartz fragment

Silicon Dioxide (SiO2)

Amethyst

Quartz (Silicon Dioxide) - SiO2 with Iron impurities

Amazonite

Potassium Feldspar (Microcline) - K(AlSi3O8)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Aquamarine (Rough)

Beryl (Be3Al2Si6O18)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Amazonite

Microcline (variety Amazonite), K(AlSi3O8)

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz (River Stone)

Silicon Dioxide (SiO2)

Amethyst

Crystalline Silicon Dioxide with Iron impurities (SiO2)

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Basalt (River Stone)

Basalt (Extrusive Igneous Rock)