Rock Identifier

Category

Volcanic Glass (Igneous)

Browse volcanic glass (igneous) specimens identified by the Rock Identifier community.

Learn about Volcanic Glass (Igneous) in the encyclopedia

Black Obsidian

Pink Obsidian

Sideromelane

Obsidian

Tachylite

Perlite

Yellow Obsidian

Yellow Obsidian

Turquoise Obsidian

Teal Obsidian

Green Sheen Obsidian

Clear Obsidian

Cobalt Blue Obsidian

Black Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Black Obsidian

Volcanic Glass (predominantly SiO2)

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

Obsidian (Obsidian (volcanic glass; primarily SiO2)) — igneous

Obsidian

Obsidian (volcanic glass; primarily SiO2)

Black obsidian (likely) (Volcanic glass; predominantly rhyolitic, silica-rich glass (approximately 70–80% SiO₂)) — igneous

Black obsidian (likely)

Volcanic glass; predominantly rhyolitic, silica-rich glass (approximately 70–80% SiO₂)

Snowflake Obsidian (Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)

Obsidian arrowhead (Volcanic glass (predominantly rhyolitic SiO₂)) — igneous

Obsidian arrowhead

Volcanic glass (predominantly rhyolitic SiO₂)

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

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Snowflake obsidian (Volcanic glass (predominantly SiO₂) with spherulitic cristobalite or feldspar inclusions) — igneous

Snowflake obsidian

Volcanic glass (predominantly SiO₂) with spherulitic cristobalite or feldspar inclusions

Pumice (Pumice, a highly vesicular volcanic glass, commonly rhyolitic to dacitic in composition) — igneous

Pumice

Pumice, a highly vesicular volcanic glass, commonly rhyolitic to dacitic in composition

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

Pumice

Pumice; highly vesicular volcanic glass, primarily rhyolitic to dacitic composition

Pumice (Highly vesicular volcanic rock, typically rhyolitic to andesitic in composition) — igneous

Pumice

Highly vesicular volcanic rock, typically rhyolitic to andesitic in composition

Pumice (Pumice (Vitreous volcanic rock)) — igneous

Pumice

Pumice (Vitreous volcanic rock)

Snowflake Obsidian (Volcanic Glass (SiO2) with Cristobalite inclusions) — igneous

Snowflake Obsidian

Volcanic Glass (SiO2) with Cristobalite inclusions

Pumice (Highly vesicular volcanic rock, commonly rhyolitic to dacitic glass (SiO₂-rich volcanic material)) — igneous

Pumice

Highly vesicular volcanic rock, commonly rhyolitic to dacitic glass (SiO₂-rich volcanic material)

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

Rhyolite

Rhyolite (High-silica volcanic rock)

Snowflake Obsidian (Volcanic glass with Spherulite inclusions (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass with Spherulite inclusions (SiO2)

Tumbled snowflake obsidian (Obsidian (volcanic glass), commonly with cristobalite spherulites) — igneous

Tumbled snowflake obsidian

Obsidian (volcanic glass), commonly with cristobalite spherulites

Small vesicular volcanic rock, likely scoria (Scoria; predominantly basaltic to andesitic volcanic rock) — igneous

Small vesicular volcanic rock, likely scoria

Scoria; predominantly basaltic to andesitic volcanic rock

Pumice (Pumice (Vitreous pyroclastic rock)) — igneous

Pumice

Pumice (Vitreous pyroclastic rock)

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

Obsidian

Volcanic Glass (70-75% SiO2)

Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.) (Mixed Silicates and Sulfides (SiO2, FeS2)) — mineral

Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)

Mixed Silicates and Sulfides (SiO2, FeS2)

Vesicular volcanic rock (likely scoria) (Scoria; vesicular basaltic to andesitic volcanic rock) — igneous

Vesicular volcanic rock (likely scoria)

Scoria; vesicular basaltic to andesitic volcanic rock

Pumice (Pumice (Volcanic silicate glass)) — igneous

Pumice

Pumice (Volcanic silicate glass)

Obsidian (Black) (Obsidian (High-silica volcanic glass)) — igneous

Obsidian (Black)

Obsidian (High-silica volcanic glass)

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

Pumice

Pumice (a vesicular volcanic glass)

Pumice (Highly vesicular volcanic rock, typically rhyolitic to andesitic in composition; mainly silica-rich volcanic glass with feldspar and minor quartz or ferromagnesian minerals.) — igneous

Pumice

Highly vesicular volcanic rock, typically rhyolitic to andesitic in composition; mainly silica-rich volcanic glass with feldspar and minor quartz or ferromagnesian minerals.

Polished black stone, possibly obsidian (Volcanic glass (obsidian), chiefly amorphous SiO₂) — igneous

Polished black stone, possibly obsidian

Volcanic glass (obsidian), chiefly amorphous SiO₂

Obsidian (Volcanic Glass (Amorphous silicon dioxide with impurities)) — igneous

Obsidian

Volcanic Glass (Amorphous silicon dioxide with impurities)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

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

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

Obsidian

Volcanic glass (SiO2 + impurities)

Pumice (Pumice (Volcanic Rock / Glass Foam)) — igneous

Pumice

Pumice (Volcanic Rock / Glass Foam)

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

Pumice

Pumice (a highly vesicular volcanic glass)

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

Mahogany Obsidian

Volcanic Glass (SiO2 with iron and magnesium oxides)

Iron-rich, vesicular volcanic rock (possibly scoria) (Scoria, likely basaltic; exact identification requires examination and testing) — igneous

Iron-rich, vesicular volcanic rock (possibly scoria)

Scoria, likely basaltic; exact identification requires examination and testing

Tumbled black stone, likely black obsidian (Obsidian — natural volcanic glass, predominantly silica-rich rhyolitic composition) — igneous

Tumbled black stone, likely black obsidian

Obsidian — natural volcanic glass, predominantly silica-rich rhyolitic composition

Snowflake Obsidian (Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)

Weathered rhyolitic tuff or altered volcanic rock (Felsic volcanic tuff, likely devitrified or hydrothermally altered) — igneous

Weathered rhyolitic tuff or altered volcanic rock

Felsic volcanic tuff, likely devitrified or hydrothermally altered

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

Pumice

Pumice (a frothy volcanic glass)

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

Black Obsidian

Volcanic Glass (SiO2 with impurities)

Obsidian (Volcanic glass; chiefly rhyolitic silica glass (SiO₂-rich, commonly ~70–80% SiO₂)) — igneous

Obsidian

Volcanic glass; chiefly rhyolitic silica glass (SiO₂-rich, commonly ~70–80% SiO₂)

Polished ocean jasper or orbicular rhyolite (Silicified, spherulitic rhyolite; chiefly quartz, feldspar, and chalcedony) — igneous

Polished ocean jasper or orbicular rhyolite

Silicified, spherulitic rhyolite; chiefly quartz, feldspar, and chalcedony