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

Asphalt Rock

Rock Salt

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Black Obsidian

Obsidian

Pink Obsidian

Sideromelane

Carbonatite

Tachylite

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Weathered granite or granitic gneiss (Granite; predominantly quartz, feldspar, and mica, possibly altered to gneiss) — igneous

Weathered granite or granitic gneiss

Granite; predominantly quartz, feldspar, and mica, possibly altered to gneiss

Basalt (Vesicular/Scoriaceous) (Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)) — Igneous

Basalt (Vesicular/Scoriaceous)

Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Greenstone Pebble (Metabasalt (often containing chlorite, actinolite, or epidote)) — metamorphic

Greenstone Pebble

Metabasalt (often containing chlorite, actinolite, or epidote)

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

Obsidian

Volcanic Glass (70% or more SiO2)

Druzzy Quartz on Matrix (Silicon Dioxide (SiO2)) — mineral

Druzzy Quartz on Matrix

Silicon Dioxide (SiO2)

Tumbled mahogany obsidian (Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions) — igneous

Tumbled mahogany obsidian

Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions

Dalmatian Stone (often called Dalmatian Jasper) (Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)) — igneous

Dalmatian Stone (often called Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)

Granodiorite (Granodiorite (intermediate plutonic rock)) — igneous

Granodiorite

Granodiorite (intermediate plutonic rock)

Obsidian (Obsidian (principally SiO2)) — igneous

Obsidian

Obsidian (principally SiO2)

Vesicular basalt (likely weathered lava rock) (Basalt, predominantly calcium-rich plagioclase, pyroxene, and commonly olivine; vesicular texture from gas bubbles) — igneous

Vesicular basalt (likely weathered lava rock)

Basalt, predominantly calcium-rich plagioclase, pyroxene, and commonly olivine; vesicular texture from gas bubbles

Chalcedony (Dyed Agate and Citrine-style Quartz) (Silicon Dioxide (SiO2)) — gemstone

Chalcedony (Dyed Agate and Citrine-style Quartz)

Silicon Dioxide (SiO2)

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

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Vesicular Basalt (Extrusive mafic igneous rock (primarily Plagioclase feldspar and Pyroxene)) — igneous

Vesicular Basalt

Extrusive mafic igneous rock (primarily Plagioclase feldspar and Pyroxene)

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

Obsidian

Volcanic Glass (Amorphous silicon dioxide with trace impurities)

Basalt (Mafic volcanic rock (formula varies by mineral content: Ca-plagioclase, Pyroxene, Olivine)) — igneous

Basalt

Mafic volcanic rock (formula varies by mineral content: Ca-plagioclase, Pyroxene, Olivine)

Quartz-rich granite or pegmatitic rock (Granite/pegmatite; chiefly quartz (SiO₂), feldspar, and minor mica) — igneous

Quartz-rich granite or pegmatitic rock

Granite/pegmatite; chiefly quartz (SiO₂), feldspar, and minor mica

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

Obsidian

Volcanic Glass (70% or more SiO2)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Basalt with Quartz Veining (Mafic Volcanic Rock with Silicate Micro-veins) — igneous

Basalt with Quartz Veining

Mafic Volcanic Rock with Silicate Micro-veins

Basalt (Basalt) — igneous

Basalt

Basalt

Quartzite with Feldspar and Mica (Granitic Gneiss Pebble) (Metamorphic Rock / Quartzite / Granitic Gneiss) — metamorphic

Quartzite with Feldspar and Mica (Granitic Gneiss Pebble)

Metamorphic Rock / Quartzite / Granitic Gneiss

Breciated Jasper (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Breciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt) — igneous

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

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

Black Obsidian (Faceted)

Volcanic Glass (Amorphous Silicon Dioxide)

Rose Quartz (Silicon Dioxide (SiO2) with trace Titanium or Manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace Titanium or Manganese

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurity)

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

Obsidian

Volcanic Glass (70-75% SiO2)

Milky Quartz Pebble (Crystalline Quartz (SiO2)) — mineral

Milky Quartz Pebble

Crystalline Quartz (SiO2)

Amethyst (Scepter/Double Terminated Point) (Silicon Dioxide (SiO2)) — mineral

Amethyst (Scepter/Double Terminated Point)

Silicon Dioxide (SiO2)

Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock) (Epidotized Metamorphic/Igneous Rock) — metamorphic

Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock)

Epidotized Metamorphic/Igneous Rock

Basalt (Basalt) — igneous

Basalt

Basalt

Clear Quartz Crystal (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Basalt (Basalt) — igneous

Basalt

Basalt

Jasper in Quartz (River Cobble) (Silicon Dioxide (SiO2) with Ferric Iron inclusions) — sedimentary

Jasper in Quartz (River Cobble)

Silicon Dioxide (SiO2) with Ferric Iron inclusions

Vesicular basalt (likely weathered volcanic rock) (Basalt, commonly composed of plagioclase, pyroxene, and olivine) — igneous

Vesicular basalt (likely weathered volcanic rock)

Basalt, commonly composed of plagioclase, pyroxene, and olivine

Gabbro (Gabbro (mafic intrusive rock)) — igneous

Gabbro

Gabbro (mafic intrusive rock)

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)