Basalt River Stone
Basalt (Mafic volcanic rock)
igneous
Category
Igneous Rock (Volcanic Glass)
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Learn about Igneous Rock (Volcanic Glass) in the encyclopedia
View all →
Tumbled Agate
Silicon Dioxide (Chalcedony variety), SiO2
mineral
Basalt Pebble
Extrusive Igneous Rock / Basalt
igneous
Likely green obsidian or dark green volcanic glass
Obsidian, a rhyolitic volcanic glass; exact identification requires testing
igneous
Vesicular basalt (likely weathered basaltic rock)
Basalt; predominantly plagioclase, clinopyroxene, olivine, and volcanic glass
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Porphyry
Porphyritic igneous rock
igneous
Scoria (Volcanic Cinder)
Extrusive Igneous Rock
igneous
Basalt
Mafic Igneous Rock
igneous
Rounded porphyritic basalt (vesicular volcanic rock)
Basalt, likely olivine- and pyroxene-bearing; approximate composition: plagioclase + clinopyroxene ± olivine and iron oxides
igneous
Obsidian
Obsidian (principally SiO2)
igneous
Likely basalt or vesicular volcanic rock
Basalt, possibly scoriaceous basalt; exact identification is uncertain from the photograph
igneous
Pumice or vesicular volcanic rock
Pumice; chiefly volcanic glass with variable feldspar, quartz, and other silicates
igneous
Basalt Pebble
Extrusive igneous rock
igneous
Vesicular volcanic rock, likely pumice or weathered scoria
Pumice/scoria; predominantly volcanic glass and plagioclase, with possible pyroxene or iron oxides
igneous
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Matrix
igneous/metamorphic
Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Polished basalt pebble
Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine
igneous
Basalt (Vesicular)
Vesicular Basalt
igneous
Basalt (Weathered)
Mafic Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Iron-stained weathered volcanic rock (probable basalt/andesite)
Altered basaltic–andesitic rock, chiefly plagioclase and pyroxene with iron oxides/hydroxides
igneous
Basalt Pebble
Extrusive Igneous Rock
igneous
Basalt (Tumbled Massage Stone)
Extrusive Igneous Rock
igneous
Polished black stone, likely gabbro or black basalt
Gabbro/basalt; chiefly plagioclase feldspar and pyroxene, possibly minor magnetite
igneous
Black obsidian (likely)
Volcanic glass; primarily silica-rich, noncrystalline SiO₂ composition
igneous
Granite (likely biotite granite or granodiorite)
Coarse-grained granitoid composed mainly of quartz, feldspar, and dark biotite/amphibole
igneous
Pumice
Pumice (a highly vesicular extrusive igneous rock, primarily amorphous silica)
igneous
Kimberlite
Ultramafic igneous rock
igneous
Vesicular Basalt
Extrusive Mafic Igneous Rock
igneous