Rock Identifier

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

Rock Gypsum

Coral Rock

Rock Salt

Asphalt Rock

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Black Obsidian

Obsidian

Pink Obsidian

Sideromelane

Carbonatite

Tachylite

Porous volcanic rock (likely pumice) (Pumice; vesicular volcanic glass, typically silica-rich) — igneous

Porous volcanic rock (likely pumice)

Pumice; vesicular volcanic glass, typically silica-rich

Pumice (Pumice (a highly vesicular felsic volcanic rock)) — igneous

Pumice

Pumice (a highly vesicular felsic volcanic rock)

Likely pumice (Pumice, vesicular volcanic glass (typically rhyolitic to dacitic composition)) — igneous

Likely pumice

Pumice, vesicular volcanic glass (typically rhyolitic to dacitic composition)

Pumice (Pumice (Highly vesicular felsic extrusive igneous rock; primarily SiO2)) — igneous

Pumice

Pumice (Highly vesicular felsic extrusive igneous rock; primarily SiO2)

Rounded gray river pebble, likely basalt or andesite (Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase ± pyroxene/olivine)) — igneous

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase ± pyroxene/olivine)

Basalt (Extrusive Igneous Rock) — igneous

Basalt

Extrusive Igneous Rock

Tumbled dark volcanic rock, possibly basalt (Basalt; commonly composed of plagioclase feldspar, pyroxene, and minor olivine or magnetite) — igneous

Tumbled dark volcanic rock, possibly basalt

Basalt; commonly composed of plagioclase feldspar, pyroxene, and minor olivine or magnetite

Possible obsidian or slag glass (Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag) — igneous

Possible obsidian or slag glass

Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag

Scoria (Extrusive Basaltic Scoria) — igneous

Scoria

Extrusive Basaltic Scoria

Agate (Silicon Dioxide (Chalcedony), SiO2) — sedimentary

Agate

Silicon Dioxide (Chalcedony), SiO2

Obsidian (Obsidian (Volcanic Glass, SiO2 + impurities)) — igneous

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Cantera Opal (Mexican Matrix Opal) (Hydrated silica in rhyolite host rock (SiO2·nH2O in Rhyolite)) — gemstone

Cantera Opal (Mexican Matrix Opal)

Hydrated silica in rhyolite host rock (SiO2·nH2O in Rhyolite)

Pumice (Pumice (Vesicular Felsic Igneous Rock)) — igneous

Pumice

Pumice (Vesicular Felsic Igneous Rock)

Pumice (Vesicular volcanic glass (primarily Alumino-silicates)) — igneous

Pumice

Vesicular volcanic glass (primarily Alumino-silicates)

Rhyolite (Rhyolite (Extrusive Felsic Igneous Rock)) — igneous

Rhyolite

Rhyolite (Extrusive Felsic Igneous Rock)

Pumice (Felsic/intermediate vesicular extrusive rock) — igneous

Pumice

Felsic/intermediate vesicular extrusive rock

Pumice (Pumice (a highly vesicular volcanic rock)) — igneous

Pumice

Pumice (a highly vesicular volcanic rock)

Quartz vein in dark host rock (Quartz (SiO₂), likely within basalt, diabase, or another mafic volcanic rock) — igneous

Quartz vein in dark host rock

Quartz (SiO₂), likely within basalt, diabase, or another mafic volcanic rock

Weathered basalt boulder (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine) — igneous

Weathered basalt boulder

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Basalt (Polished River Stone) (Aphanitic Mafic Igneous Rock) — igneous

Basalt (Polished River Stone)

Aphanitic Mafic Igneous Rock

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide, SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide, SiO2)

Slag (Industrial Glass/Glassy Rock) (Anthropogenic Vitreous Material) — igneous

Slag (Industrial Glass/Glassy Rock)

Anthropogenic Vitreous Material

Black volcanic glass or basalt pendant (Likely basalt (fine-grained mafic rock), possibly obsidian (volcanic glass)) — igneous

Black volcanic glass or basalt pendant

Likely basalt (fine-grained mafic rock), possibly obsidian (volcanic glass)

Basalt (Basalt) — igneous

Basalt

Basalt

Vesicular volcanic rock, likely scoria (Scoria; predominantly basaltic or andesitic volcanic glass with plagioclase, pyroxene, and possible iron oxides) — igneous

Vesicular volcanic rock, likely scoria

Scoria; predominantly basaltic or andesitic volcanic glass with plagioclase, pyroxene, and possible iron oxides

Vesicular volcanic rock, likely pumice or scoria (Vesicular rhyolitic–andesitic volcanic rock; predominantly silicate glass with feldspar and possibly pyroxene) — igneous

Vesicular volcanic rock, likely pumice or scoria

Vesicular rhyolitic–andesitic volcanic rock; predominantly silicate glass with feldspar and possibly pyroxene

Basalt with Olivine and Scoria (Extrusive Igneous Rock) — igneous

Basalt with Olivine and Scoria

Extrusive Igneous Rock

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Vesicular volcanic rock, likely scoria (Scoria (mafic volcanic vesicular basalt), chiefly plagioclase, pyroxene, olivine, and volcanic glass) — igneous

Vesicular volcanic rock, likely scoria

Scoria (mafic volcanic vesicular basalt), chiefly plagioclase, pyroxene, olivine, and volcanic glass

Vesicular volcanic rock, likely pumice or scoriaceous basalt (Pumice (highly vesicular volcanic glass) or vesicular basalt; exact identification requires testing) — igneous

Vesicular volcanic rock, likely pumice or scoriaceous basalt

Pumice (highly vesicular volcanic glass) or vesicular basalt; exact identification requires testing

Weathered mafic rock, likely basalt (Basalt; fine-grained plagioclase–pyroxene rock, commonly with olivine and iron oxides) — igneous

Weathered mafic rock, likely basalt

Basalt; fine-grained plagioclase–pyroxene rock, commonly with olivine and iron oxides

Light-colored volcanic rock fragment, likely pumice or tuff (Pumice (vesicular volcanic glass) or volcanic tuff; not identifiable more precisely from the image) — igneous

Light-colored volcanic rock fragment, likely pumice or tuff

Pumice (vesicular volcanic glass) or volcanic tuff; not identifiable more precisely from the image

Basalt (Extrusive Igneous Rock) — igneous

Basalt

Extrusive Igneous Rock

Basalt (Extrusive Igneous Rock) — igneous

Basalt

Extrusive Igneous Rock

Basalt (Extrusive igneous rock) — igneous

Basalt

Extrusive igneous rock

Obsidian (Volcanic Glass (SiO2, usually 70% or more)) — igneous

Obsidian

Volcanic Glass (SiO2, usually 70% or more)

Vesicular volcanic rock (likely pumice or scoria) (Pumice/scoria; predominantly volcanic glass and feldspar-rich silicate material) — igneous

Vesicular volcanic rock (likely pumice or scoria)

Pumice/scoria; predominantly volcanic glass and feldspar-rich silicate material

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Rounded basalt cobble (Basalt, aphanitic mafic volcanic rock; commonly plagioclase + clinopyroxene ± olivine and iron-titanium oxides) — igneous

Rounded basalt cobble

Basalt, aphanitic mafic volcanic rock; commonly plagioclase + clinopyroxene ± olivine and iron-titanium oxides

Basalt (Extrusive igneous rock) — igneous

Basalt

Extrusive igneous rock

Basalt with Quartz Veins (Basalt with Quartz or Calcite Veining) — igneous

Basalt with Quartz Veins

Basalt with Quartz or Calcite Veining