Basalt

River Rocks (Black)

Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts

Basalt River Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

Vesicular Basalt (Lava Rock)

Aphanitic Mafic Igneous Rock

Basalt Pebble

Basalt (Extrusive Mafic Igneous)

Basalt (River Pebble)

Extrusive mafic igneous rock

Basalt Beach Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

Basalt (with Brass Inlay)

Basalt (Mafic volcanic rock)

Basalt River Cobble

Basalt (Mafic Igneous Rock)

Basalt (with possible iron oxide staining)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Basalt River Stones

Aphantic Mafic Igneous Rock (Basalt)

Basalt (River Pebble)

Extrusive mafic igneous rock

Basalt (Beach Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Water-worn Pebble)

Basalt (Mafic volcanic rock)

Granodiorite

Phaneritic intrusive igneous rock (Granodiorite)

Basalt River Stone

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (tumbled/river-worn)

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Basalt (Weathered)

Extrusive Igneous Rock (Mafic composition)

Basalt with Quartz/Plagioclase Inclusions

Mafic volcanic rock (Basaltic)

Vesicular Basalt

Basalt (principally Plagioclase and Pyroxene)

Basalt Beach Pebble

Basalt (Aphanitic Mafic Igneous Rock)

River Stone (Basalt)

Basalt (Aphanitic Mafic Igneous Rock)

Amygdaloidal Basalt

Basalt with secondary amygdule minerals (likely Epidote or Chlorite)

Basalt with Caliche

Extrusive Mafic Igneous Rock with Secondary Carbonate Crust

Amethyst Geode

Silicon Dioxide (SiO2) with iron impurities

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Volcanic Rock)

Olivine (Peridot)

Olivine Group (Mg,Fe)2SiO4

Basalt with Vesicular Texture

Basalt (SiO2 range 45-52%)

Vesicular Basalt

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Basalt with Calcite Veins

Basalt (containing CaCO3 inclusions)

Labradorite

Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8

Carnelian (Orange Chalcedony)

Silicon dioxide (SiO2)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Basalt with Secondary Mineral Inclusions

Amygdaloidal Basalt (Mafic volcanic rock, primarily Augite and Plagioclase)

Basalt River Pebble

Basalt (Mafic volcanic rock)

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Basalt with Quartz/Calcite matrix

Basalt (SiO2 with Ca/Mg/Fe silicates) on a Mineral Matrix

Granodiorite

Phaneritic Granodiorite

Basalt River Stone

Basalt (Aphanitic Mafic Igneous Rock)

Vesicular Basalt (or Scoria)

Basalt (Aphanitic-Vesicular Mafic Igneous Rock)

Basalt River Rock

Basalt (Aphanitic Mafic Igneous Rock)

Basalt Cobble

Vesicular Basalt (Mafic Extrusive)

Basalt with Iron Oxidation

Vesicular Basalt (Aphanitic Mafic Igneous Rock)