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 (Amorphous volcanic glass (primarily SiO2)) — igneous

Black Obsidian

Amorphous volcanic glass (primarily SiO2)

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

Polished Black Obsidian

Volcanic Glass (70-75% SiO2)

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

Snowflake Obsidian

Obsidian with Spherulitic Cristobalite (SiO2)

Obsidian (Volcanic Glass (Amorphous Silica, SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous Silica, SiO2)

Pumice (Pumice (Glassy Volcanic Rock)) — igneous

Pumice

Pumice (Glassy Volcanic Rock)

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

Obsidian / Volcanic Glass

Obsidian (principally SiO2, usually 70% or more)

Obsidian (likely black obsidian) (Volcanic glass; predominantly rhyolitic composition (approximately 70–80% SiO₂)) — igneous

Obsidian (likely black obsidian)

Volcanic glass; predominantly rhyolitic composition (approximately 70–80% SiO₂)

Pumice (Pumice (extrusive volcanic rock)) — igneous

Pumice

Pumice (extrusive volcanic rock)

Black obsidian (likely) (Volcanic glass; primarily silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)) — igneous

Black obsidian (likely)

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

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads) (Obsidian (volcanic glass, predominantly SiO2 with various impurities)) — Igneous

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads)

Obsidian (volcanic glass, predominantly SiO2 with various impurities)

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

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Glass/Rock)

Polished mahogany obsidian (likely) pendant (Obsidian, natural volcanic glass; compositionally rhyolitic, chiefly silica-rich glass) — igneous

Polished mahogany obsidian (likely) pendant

Obsidian, natural volcanic glass; compositionally rhyolitic, chiefly silica-rich glass

Pumice (Pumice, a highly vesicular volcanic glass composed mainly of rhyolitic to dacitic silicate material) — igneous

Pumice

Pumice, a highly vesicular volcanic glass composed mainly of rhyolitic to dacitic silicate material

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

Likely pumice

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

Scoria (vesicular basalt) (Vesicular basalt; primarily plagioclase, pyroxene, olivine, and volcanic glass) — igneous

Scoria (vesicular basalt)

Vesicular basalt; primarily plagioclase, pyroxene, olivine, and volcanic glass

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

Obsidian

Volcanic Glass (70% or more SiO2)

Polished black obsidian (Volcanic glass, primarily rhyolitic silica (SiO₂)) — igneous

Polished black obsidian

Volcanic glass, primarily rhyolitic silica (SiO₂)

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

Snowflake Obsidian

Volcanic Glass with Spherulitic Cristobalite (SiO2)

Polished silver sheen obsidian heart (Obsidian (volcanic glass), primarily rhyolitic silica-rich glass) — igneous

Polished silver sheen obsidian heart

Obsidian (volcanic glass), primarily rhyolitic silica-rich glass

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

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Obsidian (likely black obsidian) (Volcanic glass; chiefly silica-rich rhyolitic composition, approximately SiO₂ 70–75%) — igneous

Obsidian (likely black obsidian)

Volcanic glass; chiefly silica-rich rhyolitic composition, approximately SiO₂ 70–75%

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Pumice (Pumice (Vesicular felsic extrusive igneous rock)) — igneous

Pumice

Pumice (Vesicular felsic extrusive igneous rock)

Weathered vesicular volcanic rock, likely basaltic scoria (Vesicular basalt/scoria; chiefly plagioclase, pyroxene, olivine, and volcanic glass) — igneous

Weathered vesicular volcanic rock, likely basaltic scoria

Vesicular basalt/scoria; chiefly plagioclase, pyroxene, olivine, and volcanic glass

Pumice (Pumice (Volcanic Rock)) — igneous

Pumice

Pumice (Volcanic Rock)

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

Pumice

Pumice (Vesicular Rhyolite/Andesite)

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

Polished black stone, likely black obsidian

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

Basalt (Pahoehoe texture) (Mafic Volcanic Rock) — igneous

Basalt (Pahoehoe texture)

Mafic Volcanic Rock

Tumbled Obsidian (possibly Mahogany Obsidian variant) (Volcanic Glass (Amorphous Silicon Dioxide, SiO2)) — igneous

Tumbled Obsidian (possibly Mahogany Obsidian variant)

Volcanic Glass (Amorphous Silicon Dioxide, SiO2)

Pumice (Vesicular Rhyolite or Andesite (Amorphous volcanic glass)) — igneous

Pumice

Vesicular Rhyolite or Andesite (Amorphous volcanic glass)

Pumice (Pumice) — igneous

Pumice

Pumice

Pumice (Pumice) — igneous

Pumice

Pumice

Pumice (Pumice) — igneous

Pumice

Pumice

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

Pumice

Pumice (Volcanic Rock / Glass Froth)

Pumice (Pumice (Vesicular Felsic Glass)) — igneous

Pumice

Pumice (Vesicular Felsic Glass)

Likely tumbled black stone or glassy mineral (Indeterminate from image; possibilities include obsidian, hematite, or black tourmaline) — mineral

Likely tumbled black stone or glassy mineral

Indeterminate from image; possibilities include obsidian, hematite, or black tourmaline

Quartz Druze (Crystalline Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz Druze (Crystalline Quartz)

Silicon Dioxide (SiO2)

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 (Volcanic glass / Felsic igneous rock)) — igneous

Pumice

Pumice (Volcanic glass / Felsic igneous rock)

Polished black stone, likely black obsidian (Obsidian (volcanic glass; chiefly silica-rich rhyolitic composition)) — igneous

Polished black stone, likely black obsidian

Obsidian (volcanic glass; chiefly silica-rich rhyolitic composition)

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

Obsidian

Amorphous volcanic glass (primarily SiO2)

Snowflake Obsidian (Obsidian with Cristobalite inclusions (mostly amorphous SiO2)) — igneous

Snowflake Obsidian

Obsidian with Cristobalite inclusions (mostly amorphous SiO2)