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

Pumice or Tufa/Travertine (Pumice (if igneous) or Calcareous Tufa (if sedimentary)) — igneous/sedimentary

Pumice or Tufa/Travertine

Pumice (if igneous) or Calcareous Tufa (if sedimentary)

igneous/sedimentary

Pumice (Vesicular Rhyolite / Glassy Igneous Rock) — igneous

Pumice

Vesicular Rhyolite / Glassy Igneous Rock

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

Pumice

Pumice; highly vesicular volcanic glass, typically rhyolitic to dacitic in composition

Obsidian (volcanic glass) (Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides) — igneous

Obsidian (volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

Pumice (Pumice, vesicular volcanic glass (typically silica-rich rhyolite or dacite composition)) — igneous

Pumice

Pumice, vesicular volcanic glass (typically silica-rich rhyolite or dacite composition)

Weathered conglomeratic volcanic rock (Likely basaltic volcanic breccia or agglomerate, with plagioclase, pyroxene, volcanic glass, and lithic fragments) — igneous

Weathered conglomeratic volcanic rock

Likely basaltic volcanic breccia or agglomerate, with plagioclase, pyroxene, volcanic glass, and lithic fragments

Polished black stone, likely basalt or black jasper (Indeterminate; possible fine-grained basalt (plagioclase–pyroxene) or black jasper/microcrystalline quartz) — igneous

Polished black stone, likely basalt or black jasper

Indeterminate; possible fine-grained basalt (plagioclase–pyroxene) or black jasper/microcrystalline quartz

Unidentified Dark Mineral or Rock (Indeterminate (Likely Silicon Dioxide or Carbon-based)) — mineral

Unidentified Dark Mineral or Rock

Indeterminate (Likely Silicon Dioxide or Carbon-based)

Obsidian (Obsidian (principally SiO2 silicon dioxide)) — igneous

Obsidian

Obsidian (principally SiO2 silicon dioxide)

Polished obsidian (likely snowflake obsidian) (Volcanic glass, chiefly rhyolitic; snowflake patterns are cristobalite/spherulites in obsidian) — igneous

Polished obsidian (likely snowflake obsidian)

Volcanic glass, chiefly rhyolitic; snowflake patterns are cristobalite/spherulites in obsidian

Polished black stone, likely black obsidian (Obsidian (volcanic glass), primarily rhyolitic silica glass) — igneous

Polished black stone, likely black obsidian

Obsidian (volcanic glass), primarily rhyolitic silica glass

Tumbled rhyolite (likely) (Rhyolite, a felsic volcanic rock composed mainly of quartz and alkali feldspar, with biotite or hornblende) — igneous

Tumbled rhyolite (likely)

Rhyolite, a felsic volcanic rock composed mainly of quartz and alkali feldspar, with biotite or hornblende

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurity)

Pumice (Pumicite) — igneous

Pumice

Pumicite

Mahogany obsidian crystal point (Volcanic glass, primarily rhyolitic silica (SiO₂), with iron-oxide inclusions) — igneous

Mahogany obsidian crystal point

Volcanic glass, primarily rhyolitic silica (SiO₂), with iron-oxide inclusions

Black Obsidian (Obsidian / Amorphous volcanic glass (SiO2)) — igneous

Black Obsidian

Obsidian / Amorphous volcanic glass (SiO2)

Pumice (Pumice (extrusive volcanic rock)) — igneous

Pumice

Pumice (extrusive volcanic rock)

Likely obsidian (black volcanic glass) (Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂) — igneous

Likely obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂

Polished mahogany obsidian (Obsidian, natural volcanic glass; predominantly silica-rich rhyolitic glass (SiO₂)) — igneous

Polished mahogany obsidian

Obsidian, natural volcanic glass; predominantly silica-rich rhyolitic glass (SiO₂)

Basalt Pebble (Extrusive Igneous Rock (Mafic)) — igneous

Basalt Pebble

Extrusive Igneous Rock (Mafic)

Polished dark pebble, likely basalt or chert (Basalt (mafic volcanic rock), possibly microcrystalline chert) — igneous

Polished dark pebble, likely basalt or chert

Basalt (mafic volcanic rock), possibly microcrystalline chert

Obsidian (Obsidian (Volcanic Glass, ~70% SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

Pumice (Pumice (Volcanic Rock)) — igneous

Pumice

Pumice (Volcanic Rock)

Mixed Mineral Collection (Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)) — mineral

Mixed Mineral Collection

Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)

Scoria (vesicular basalt) (Vesicular basalt; chiefly plagioclase, pyroxene, and iron-rich glass) — igneous

Scoria (vesicular basalt)

Vesicular basalt; chiefly plagioclase, pyroxene, and iron-rich glass

Likely obsidian (possibly tektite or slag glass) (Volcanic glass; primarily SiO₂, noncrystalline) — igneous

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Polished obsidian (Volcanic glass; predominantly rhyolitic SiO₂) — igneous

Polished obsidian

Volcanic glass; predominantly rhyolitic SiO₂

Basalt (Basalt) — igneous

Basalt

Basalt

Obsidian (black volcanic glass) (Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides) — igneous

Obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

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 (Vesicular Rhyolite/Dacite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Dacite)

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

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Glass (Amorphous Silicon Dioxide (SiO2)) — mineraloid

Glass

Amorphous Silicon Dioxide (SiO2)

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

Pumice

Pumice (a highly vesicular amorphous volcanic glass)

Obsidian (black volcanic glass) (Obsidian; silica-rich volcanic glass, typically rhyolitic to dacitic composition) — igneous

Obsidian (black volcanic glass)

Obsidian; silica-rich volcanic glass, typically rhyolitic to dacitic composition

Scoria (vesicular volcanic rock) (Scoria, typically basaltic or andesitic volcanic material) — igneous

Scoria (vesicular volcanic rock)

Scoria, typically basaltic or andesitic volcanic material

Pumice (Pumicite) — igneous

Pumice

Pumicite

Polished snowflake obsidian (Obsidian (volcanic glass), likely with cristobalite or feldspar spherulites) — igneous

Polished snowflake obsidian

Obsidian (volcanic glass), likely with cristobalite or feldspar spherulites

Basalt (Basalt) — igneous

Basalt

Basalt

Tumbled black obsidian (Obsidian, a natural volcanic glass composed chiefly of silica-rich, felsic melt) — igneous

Tumbled black obsidian

Obsidian, a natural volcanic glass composed chiefly of silica-rich, felsic melt

Pumice (Vesicular volcanic rock, primarily silica-rich volcanic glass (commonly rhyolitic or dacitic)) — igneous

Pumice

Vesicular volcanic rock, primarily silica-rich volcanic glass (commonly rhyolitic or dacitic)

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

Quartz Vein in Rhyolite

Silicon Dioxide (SiO2) in extrusive igneous rock