Rock Identifier

Category

Igneous Rock (Volcanic Glass)

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

Milky Quartz/Clear Quartz Cluster (Silicon Dioxide (SiO2)) — mineral

Milky Quartz/Clear Quartz Cluster

Silicon Dioxide (SiO2)

Amethyst (Silicon dioxide (variant with ferric iron impurities), SiO2) — mineral

Amethyst

Silicon dioxide (variant with ferric iron impurities), SiO2

Quartz (Vein Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Basalt with Weathered Rind (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt with Weathered Rind

Basalt (Aphanitic Mafic Igneous Rock)

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

Basalt (Vesicular)

Basalt (Mafic Extrusive Igneous Rock)

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)

Obsidian (Volcanic Glass (Amorphous SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous SiO2)

Diorite (Phaneritic Intermediate Plutonic Rock (Diorite)) — igneous

Diorite

Phaneritic Intermediate Plutonic Rock (Diorite)

Obsidian (Volcanic Glass (SiO2 dominant)) — igneous

Obsidian

Volcanic Glass (SiO2 dominant)

Basalt (Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)) — igneous

Basalt

Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)

Dendritic Agate (Silicon Dioxide with Manganese/Iron oxide inclusions (SiO2)) — Mineral

Dendritic Agate

Silicon Dioxide with Manganese/Iron oxide inclusions (SiO2)

Snowflake Obsidian (Volcanic glass containing Spherulites (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulites (SiO2)

Tree Agate (Silicon Dioxide with Chlorite inclusions (SiO2)) — Mineral (Variety of Chalcedony)

Tree Agate

Silicon Dioxide with Chlorite inclusions (SiO2)

Mineral (Variety of Chalcedony)

Basalt with Vesicular Surface (Basalt (Mafic Extrusive)) — igneous

Basalt with Vesicular Surface

Basalt (Mafic Extrusive)

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Granodiorite (Granodiorite (containing Plagioclase, Quartz, and K-feldspar)) — igneous

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and K-feldspar)

Basalt (Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)) — igneous

Basalt

Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)

Milky Quartz Pebble (Iron-Stained) (Silicon Dioxide (SiO2)) — mineral

Milky Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

Diorite (Diorite (intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (intermediate intrusive igneous rock)

Granite / Quartz Vein Rock (Granitoid with Quartz (SiO2)) — igneous

Granite / Quartz Vein Rock

Granitoid with Quartz (SiO2)

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)

Obsidian (Obsidian (Volcanic Glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Rainbow Obsidian (Volcanic Glass (SiO2 + impurities)) — Igneous

Rainbow Obsidian

Volcanic Glass (SiO2 + impurities)

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)

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

Scoria (Red Lava Rock) (Scoria (Vesicular basaltic rock)) — Igneous

Scoria (Red Lava Rock)

Scoria (Vesicular basaltic rock)

Basalt (Basalt) — igneous

Basalt

Basalt

Yellow Quartz (Citrine or Iron-Stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Chert (Chalcedony/Agate variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Porphyritic Basalt (Amygdaloidal Porphyritic Basalt) — igneous

Porphyritic Basalt

Amygdaloidal Porphyritic Basalt

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz Veined Basalt Pebble (Amygdaloidal Basalt with Quartz (SiO2) veining) — igneous

Quartz Veined Basalt Pebble

Amygdaloidal Basalt with Quartz (SiO2) veining

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Apache Tear (Hydrated Obsidian (Volcanic Glass)) — igneous

Apache Tear

Hydrated Obsidian (Volcanic Glass)

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

Obsidian

Volcanic Glass (SiO2 + impurities)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Apache Tear (Obsidian) (Volcanic glass / Amorphous SiO2) — igneous

Apache Tear (Obsidian)

Volcanic glass / Amorphous SiO2

Apache Tear (Obsidian (Hydrated Volcanic Glass)) — igneous

Apache Tear

Obsidian (Hydrated Volcanic Glass)

Obsidian (specifically Rainbow or Silver Sheen Obsidian) (Volcanic Glass (predominantly SiO2)) — Igneous

Obsidian (specifically Rainbow or Silver Sheen Obsidian)

Volcanic Glass (predominantly SiO2)

Mahogany Obsidian (Volcanic Glass (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)