Rock Identifier

Category

Igneous Rock (Volcanic Glass)

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

Quartz (Milky/Common) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Chalcedony (Grey/White Agate) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Grey/White Agate)

Silicon Dioxide (SiO₂)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Snowflake Obsidian (Volcanic glass containing Spherulitic Cristobalite (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulitic Cristobalite (SiO2)

Obsidian (Volcanic glass (SiO2-rich extrusive igneous rock)) — igneous

Obsidian

Volcanic glass (SiO2-rich extrusive igneous rock)

Pumice (Vesicular volcanic glass (Amorphous silica mixed with various oxides)) — igneous

Pumice

Vesicular volcanic glass (Amorphous silica mixed with various oxides)

Basalt (Basalt (composition: Plagioclase, Pyroxene, and Olivine)) — igneous

Basalt

Basalt (composition: Plagioclase, Pyroxene, and Olivine)

Apache Tear (Obsidian) (Hydrated volcanic glass (SiO2 with inclusions)) — igneous

Apache Tear (Obsidian)

Hydrated volcanic glass (SiO2 with inclusions)

Chalcedony (Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Iron-stained Milky Quartz (Silicon Dioxide (SiO2) with iron oxide inclusions) — mineral

Iron-stained Milky Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

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

Pumice

Pumice (Highly vesicular volcanic glass)

Basalt (Mafic Igneous Rock) — igneous

Basalt

Mafic Igneous Rock

Obsidian (Obsidian (volcanic glass), amorphous SiO2 + impurities) — igneous

Obsidian

Obsidian (volcanic glass), amorphous SiO2 + impurities

Pumice (Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)) — igneous

Pumice

Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)

Pumice (Pumice (volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (volcanic glass with vesicular texture)

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

Obsidian

Volcanic Glass (SiO2, usually 70% or more)

Mahogany Obsidian (Volcanic Glass with Hematite/Magnetite inclusions) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Quartz Vein in Host Rock (Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix) — igneous

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

Pumice (Pumice (volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (volcanic glass with vesicular texture)

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

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Pumice (Pumice (Volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (Volcanic glass with vesicular texture)

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

Pumice

Pumice (a highly vesicular volcanic glass)

Snowflake Obsidian (Volcanic glass with Cristobalite inclusions (70–75% SiO2)) — igneous

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Pumice (Vesicular Rhyolite or Dacite) — igneous

Pumice

Vesicular Rhyolite or Dacite

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

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

Rhyolite

Rhyolite (Extrusive Felsic Igneous Rock)

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

Basalt (Polished River Stone)

Aphanitic Mafic Igneous Rock

Quartz Vein in Host Rock (Breccia/Rhyolite) (Silicon Dioxide (SiO2) with matrix) — Mineral in Igneous/Sedimentary host

Quartz Vein in Host Rock (Breccia/Rhyolite)

Silicon Dioxide (SiO2) with matrix

Mineral in Igneous/Sedimentary host

Snowflake Obsidian (Vitreous Volcanic Rock (Amorphous Silicate), SiO2) — igneous

Snowflake Obsidian

Vitreous Volcanic Rock (Amorphous Silicate), SiO2

Obsidian (Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Pumice (Felsic Volcanic Glass / Vesicular Rhyolite) — Igneous

Pumice

Felsic Volcanic Glass / Vesicular Rhyolite

Pumice (Vesicular volcanic glass (primarily SiO2)) — igneous

Pumice

Vesicular volcanic glass (primarily SiO2)

Obsidian (Obsidian (Volcanic Glass, complex silicate)) — igneous

Obsidian

Obsidian (Volcanic Glass, complex silicate)

Obsidian (Obsidian (volcanic glass, amorphous silica rich rock)) — Igneous

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2) within Matrix) — igneous/metamorphic

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Matrix

igneous/metamorphic

Snowflake Obsidian (Vitreous volcanic silicate rock (SiO2) with Spherulite inclusions) — igneous

Snowflake Obsidian

Vitreous volcanic silicate rock (SiO2) with Spherulite inclusions

Snowflake Obsidian (Volcanic glass with Cristobalite inclusions (70–75% SiO2)) — Igneous

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Mica (Biotite or Phlogopite variety) (Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)) — mineral

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

Basalt with Scoria (Amygdaloidal Basalt / Vesicular Basalt) — igneous

Basalt with Scoria

Amygdaloidal Basalt / Vesicular Basalt

Pumice (Pumice (a volcanic glass, primarily SiO2 with Al2O3)) — igneous

Pumice

Pumice (a volcanic glass, primarily SiO2 with Al2O3)

Basalt River Stone (Basaltic Igneous Rock) — igneous

Basalt River Stone

Basaltic Igneous Rock