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

Pumice (Volcanic Rock) (Vesicular volcanic rock (composed largely of amorphous volcanic glass)) — igneous

Pumice (Volcanic Rock)

Vesicular volcanic rock (composed largely of amorphous volcanic glass)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Pumice (Pumice (highly vesicular volcanic glass; typically rhyolitic to dacitic composition)) — igneous

Pumice

Pumice (highly vesicular volcanic glass; typically rhyolitic to dacitic composition)

Rounded basalt pebble (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with minor olivine or iron oxides) — igneous

Rounded basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with minor olivine or iron oxides

Pumice (Vesicular Rhyolite/Andesite) (Pumice (a highly vesicular volcanic glass/extrusive igneous rock)) — igneous

Pumice (Vesicular Rhyolite/Andesite)

Pumice (a highly vesicular volcanic glass/extrusive igneous rock)

Rhyolite (Rhyolite (felsic volcanic rock)) — igneous

Rhyolite

Rhyolite (felsic volcanic rock)

Porous quartz-rich rock, likely weathered rhyolite or silicified volcanic breccia (Rhyolite or volcanic breccia; predominantly microcrystalline quartz (SiO₂) with altered feldspar and iron oxides) — igneous

Porous quartz-rich rock, likely weathered rhyolite or silicified volcanic breccia

Rhyolite or volcanic breccia; predominantly microcrystalline quartz (SiO₂) with altered feldspar and iron oxides

Vesicular volcanic rock, likely pumice (Pumice (highly vesicular rhyolitic–dacitic volcanic glass; composition commonly rich in quartz and feldspar)) — igneous

Vesicular volcanic rock, likely pumice

Pumice (highly vesicular rhyolitic–dacitic volcanic glass; composition commonly rich in quartz and feldspar)

Mahogany Obsidian (Volcanic Glass (SiO2 with iron and magnesium oxides)) — igneous

Mahogany Obsidian

Volcanic Glass (SiO2 with iron and magnesium oxides)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

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

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Obsidian (Volcanic Glass (70-75% SiO2)) — igneous

Obsidian

Volcanic Glass (70-75% SiO2)

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

Pumice

Pumice (a highly vesicular volcanic rock)

Pumice (Volcanic glass / Pumice) — igneous

Pumice

Volcanic glass / Pumice

Spherulitic Rhyolite / Leopard Skin Rhyolite (Extrusive felsic igneous rock with spherulites) — igneous

Spherulitic Rhyolite / Leopard Skin Rhyolite

Extrusive felsic igneous rock with spherulites

Common Opal in Host Rock (Hydrated Silica (SiO2·nH2O)) — mineraloid

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Likely obsidian (rough fragment) (Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)) — igneous

Likely obsidian (rough fragment)

Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)

Rhyolite (Rhyolite (High-silica volcanic rock)) — igneous

Rhyolite

Rhyolite (High-silica volcanic rock)

Pumice (Pumice (Vesicular Rhyolite/Dacite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Dacite)

Pumice (Pumice (Amorphous volcanic glass)) — igneous

Pumice

Pumice (Amorphous volcanic glass)

Obsidian (Volcanic Glass (Amorphous SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous SiO2)

Pumice (Pumice (a vesicular volcanic glass)) — igneous

Pumice

Pumice (a vesicular volcanic glass)

Pumice (Pumice (Vesicular Rhyolite/Andesite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Apache Tear (Hydrated Obsidian (Volcanic Glass)) — igneous

Apache Tear

Hydrated Obsidian (Volcanic Glass)

Quartz Vein in Rhyolite (Silicon Dioxide (SiO2) in extrusive igneous rock) — igneous

Quartz Vein in Rhyolite

Silicon Dioxide (SiO2) in extrusive igneous rock

Scoria (Lava Rock) (Scoria (Vesicular Basaltic Glass/Rock)) — igneous

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Glass/Rock)

Quartz vein in weathered host rock (Quartz (SiO₂), likely in a weathered metamorphic or igneous matrix) — mineral

Quartz vein in weathered host rock

Quartz (SiO₂), likely in a weathered metamorphic or igneous matrix

Pumice (Pumice (SiO2)) — igneous

Pumice

Pumice (SiO2)

Granite pebble (Granite; chiefly quartz, feldspar, and mica) — igneous

Granite pebble

Granite; chiefly quartz, feldspar, and mica

Pumice (Pumicite) — igneous

Pumice

Pumicite

Polished black stone, likely basalt or basaltic glass (Fine-grained basalt (possibly devitrified volcanic glass); mainly plagioclase and pyroxene, with iron-titanium oxides) — igneous

Polished black stone, likely basalt or basaltic glass

Fine-grained basalt (possibly devitrified volcanic glass); mainly plagioclase and pyroxene, with iron-titanium oxides

Pumice (Pumice (a frothy volcanic glass)) — igneous

Pumice

Pumice (a frothy volcanic glass)

Polished black obsidian (Volcanic glass; predominantly rhyolitic silica glass (approximately SiO₂-rich)) — igneous

Polished black obsidian

Volcanic glass; predominantly rhyolitic silica glass (approximately SiO₂-rich)

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

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

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

Obsidian

Volcanic Glass (SiO2 + impurities)

Pumice (Pumice (extrusive volcanic rock)) — igneous

Pumice

Pumice (extrusive volcanic rock)

Rhyolite (Rhyolite (High-silica volcanic rock)) — igneous

Rhyolite

Rhyolite (High-silica volcanic rock)

Obsidian with Cristobalite (Volcanic Glass (Amorphous Silicon Dioxide) with Cristobalite inclusions) — igneous

Obsidian with Cristobalite

Volcanic Glass (Amorphous Silicon Dioxide) with Cristobalite inclusions

Pumice (Vesicular Rhyolite / Glassy Igneous Rock) — igneous

Pumice

Vesicular Rhyolite / Glassy Igneous Rock

Pumice (Pumice (Vesicular Felsic to Intermediate Volcanic Rock)) — igneous

Pumice

Pumice (Vesicular Felsic to Intermediate Volcanic Rock)

Rhyolite (Rhyolite (High-silica volcanic rock)) — igneous

Rhyolite

Rhyolite (High-silica volcanic rock)

Black glassy volcanic rock, likely scoria or obsidian (Vesicular basaltic scoria (probable); possibly dark obsidian) — igneous

Black glassy volcanic rock, likely scoria or obsidian

Vesicular basaltic scoria (probable); possibly dark obsidian