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

Red jasper in gray host rock (likely hematite-stained quartzite or rhyolite) (Jasper: microcrystalline quartz (SiO₂), with iron-oxide coloration; exact host uncertain from image) — mineral

Red jasper in gray host rock (likely hematite-stained quartzite or rhyolite)

Jasper: microcrystalline quartz (SiO₂), with iron-oxide coloration; exact host uncertain from image

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

Quartz (Druzy)

Silicon Dioxide (SiO2)

Chalcedony (Common Opal variant or Agate pebble) (Silicon dioxide (SiO2)) — mineral

Chalcedony (Common Opal variant or Agate pebble)

Silicon dioxide (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Basalt (Basalt (Aphanitic Mafic Volcanic)) — igneous

Basalt

Basalt (Aphanitic Mafic Volcanic)

Scoria (Vesicular Basalt / Scoria) — igneous

Scoria

Vesicular Basalt / Scoria

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

Basalt (River Stone)

Basalt (Mafic Extrusive Igneous Rock)

Snowflake Obsidian (Obsidian with Cristobalite inclusions (mostly amorphous SiO2)) — igneous

Snowflake Obsidian

Obsidian with Cristobalite inclusions (mostly amorphous SiO2)

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

Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic volcanic rock)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Obsidian (Amorphous volcanic glass (SiO2)) — igneous

Obsidian

Amorphous volcanic glass (SiO2)

Diorite (Diorite (Intermediate Plutonic Rock)) — igneous

Diorite

Diorite (Intermediate Plutonic Rock)

Basalt with Olivine inclusion (Mafic Volcanic Basalt (Fe,Mg)2SiO4) — igneous

Basalt with Olivine inclusion

Mafic Volcanic Basalt (Fe,Mg)2SiO4

Basalt (Extrusive Mafic Igneous Rock) — igneous

Basalt

Extrusive Mafic Igneous Rock

Snowflake Obsidian (Spherulitic Volcanic Glass (SiO2)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (SiO2)

Likely tumbled basalt or dark volcanic rock (Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides) — igneous

Likely tumbled basalt or dark volcanic rock

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Basalt (Weathered) (Basalt) — igneous

Basalt (Weathered)

Basalt

Porphyritic Basalt with Quartz Inclusions (Aphanitic Porphyritic Basalt) — Igneous

Porphyritic Basalt with Quartz Inclusions

Aphanitic Porphyritic Basalt

Milky Quartz with Iron Staining (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Dark gray river pebble, likely basalt (Basalt; chiefly plagioclase feldspar, pyroxene, and minor olivine or magnetite) — igneous

Dark gray river pebble, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and minor olivine or magnetite

Weathered basalt pebble (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine) — igneous

Weathered basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Rounded basalt cobble (Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine and iron oxides) — igneous

Rounded basalt cobble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine and iron oxides

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Basalt (River Pebble) (Basalt (dominated by Plagioclase Feldspar and Pyroxene)) — igneous

Basalt (River Pebble)

Basalt (dominated by Plagioclase Feldspar and Pyroxene)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Quartz (Chert / Agate / Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Quartz (Chert / Agate / Chalcedony)

Silicon Dioxide (SiO2)

Basalt Pebble (Basalt) — igneous

Basalt Pebble

Basalt

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Diorite (River Rock/Cobble) (Intermediate Plutonic Igneous Rock (Diorite)) — igneous

Diorite (River Rock/Cobble)

Intermediate Plutonic Igneous Rock (Diorite)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Apache Tear (Obsidian) (Volcanic Glass (Amorphous SiO2)) — igneous

Apache Tear (Obsidian)

Volcanic Glass (Amorphous SiO2)

Obsidian (Polished Point/Wand) (Volcanic Glass (SiO2 with impurities)) — igneous

Obsidian (Polished Point/Wand)

Volcanic Glass (SiO2 with impurities)

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

Black Obsidian

Volcanic Glass (SiO2 with impurities)

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

Black Obsidian

Amorphous volcanic glass (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Basalt (Basalt) — igneous

Basalt

Basalt

Granodiorite (Gravel Pebble) (Granodiorite) — igneous

Granodiorite (Gravel Pebble)

Granodiorite

Likely weathered basalt or mafic volcanic rock (Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine) — igneous

Likely weathered basalt or mafic volcanic rock

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Basalt with Quartz/Feldspar Vein (Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)) — igneous

Basalt with Quartz/Feldspar Vein

Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)

Scoria (Lava Rock) (Scoria) — igneous

Scoria (Lava Rock)

Scoria