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

Granite (Felsic intrusive igneous rock) — igneous

Granite

Felsic intrusive igneous rock

Scoria (Lava Rock) (Vesicular Basalt / Scoria) — igneous

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Carnelian Agate (Silicon Dioxide (SiO2)) — mineral

Carnelian Agate

Silicon Dioxide (SiO2)

Basalt (Basalt) — igneous

Basalt

Basalt

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Diorite (River Cobble) (Intermediate Phaneritic Plutonic Rock) — Igneous

Diorite (River Cobble)

Intermediate Phaneritic Plutonic Rock

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Raw Quartz (Silicon Dioxide (SiO2)) — mineral

Raw Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst (Amethyst (Silicon Dioxide, SiO2 with Iron impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

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

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt (Mafic volcanic rock (Silicon dioxide 45-52%)) — igneous

Basalt

Mafic volcanic rock (Silicon dioxide 45-52%)

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

Clear Quartz

Silicon Dioxide (SiO2) / Rock Crystal

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Mahogany Obsidian (Volcanic Glass with Hematite inclusions (SiO2)) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 dominated)

Greenstone (Epidote/Chlorite Rich Rock) (Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))) — metamorphic

Greenstone (Epidote/Chlorite Rich Rock)

Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))

Jasper and Greenstone Pebble (Siliceous rock / Metamorphic pebble) — metamorphic

Jasper and Greenstone Pebble

Siliceous rock / Metamorphic pebble

Agate (Silicon Dioxide (Chalcedony), SiO2) — sedimentary

Agate

Silicon Dioxide (Chalcedony), SiO2

Weathered reddish-brown rock fragment (Probably altered basalt or fine-grained volcanic rock; exact identification requires testing) — igneous

Weathered reddish-brown rock fragment

Probably altered basalt or fine-grained volcanic rock; exact identification requires testing

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Tumbled gray stone, likely serpentinite or weathered basalt (Tentatively serpentinite (predominantly serpentine-group minerals); identification is uncertain from the photograph) — igneous

Tumbled gray stone, likely serpentinite or weathered basalt

Tentatively serpentinite (predominantly serpentine-group minerals); identification is uncertain from the photograph

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartz River Rock (Silicon Dioxide (SiO2)) — mineral

Quartz River Rock

Silicon Dioxide (SiO2)

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

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

K-Feldspar Granite Fragment (Felsic Plutonic Rock (Granite)) — igneous

K-Feldspar Granite Fragment

Felsic Plutonic Rock (Granite)

Diorite (Diorite (Phaneritic intermediate plutonic rock)) — igneous

Diorite

Diorite (Phaneritic intermediate plutonic rock)

Milky Quartz with Country Rock contact (Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock) — mineral

Milky Quartz with Country Rock contact

Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock

Citrine (Silicon Dioxide (SiO2)) — mineral

Citrine

Silicon Dioxide (SiO2)

Basalt (Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)) — igneous

Basalt

Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)

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

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Obsidian (Obsidian (Volcanic Glass, ~70–75% SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, ~70–75% SiO2)

Tektite (Indochinite) (Tektite (SiO2 + Al2O3, Glassy Melts)) — igneous

Tektite (Indochinite)

Tektite (SiO2 + Al2O3, Glassy Melts)

Diorite (Salt and Pepper Rock) (Diorite) — igneous

Diorite (Salt and Pepper Rock)

Diorite

Polished red jasper beads (Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides) — mineral

Polished red jasper beads

Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides

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

Quartz (Milky Quartz / Clear Quartz)

Silicon Dioxide (SiO2)

K-Feldspar (Potassium Feldspar) (Orthoclase / Microcline (KAlSi3O8)) — mineral

K-Feldspar (Potassium Feldspar)

Orthoclase / Microcline (KAlSi3O8)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Polished orbicular jasper (Orbicular jasper; microcrystalline quartz (SiO₂) with hematite/goethite and other silicate inclusions) — sedimentary

Polished orbicular jasper

Orbicular jasper; microcrystalline quartz (SiO₂) with hematite/goethite and other silicate inclusions

Snowflake Obsidian (Spherulitic Obsidian (primarily SiO2)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2)

Basalt with Caliche Crust (Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating) — igneous

Basalt with Caliche Crust

Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating