Rock Identifier

Category

Igneous Rock (Volcanic Glass)

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

Milky Quartz (with potential inclusion of feldspar) (Silicon Dioxide (SiO2)) — Mineral

Milky Quartz (with potential inclusion of feldspar)

Silicon Dioxide (SiO2)

Obsidian (Volcanic glass (high silica content based on SiO2)) — igneous

Obsidian

Volcanic glass (high silica content based on SiO2)

Quartz (Milky or White Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Basalt (Greenstone) (Amygdaloidal Basalt / Chloritized Basalt) — Igneous

Basalt (Greenstone)

Amygdaloidal Basalt / Chloritized Basalt

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

Clear Quartz (Carved Dragon)

Quartz (Silicon Dioxide, SiO2)

Quartz Pebbles (Silicon Dioxide (SiO2)) — mineral

Quartz Pebbles

Silicon Dioxide (SiO2)

Diorite (Phaneritic plutonic rock (dominated by plagioclase feldspar and hornblende)) — igneous

Diorite

Phaneritic plutonic rock (dominated by plagioclase feldspar and hornblende)

Granitic Quartz with Feldspar (Granite (composed primarily of SiO2 and KAlSi3O8)) — igneous

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Porphyritic Basalt (Porphyritic Basalt (with plagioclase phenocrysts)) — igneous

Porphyritic Basalt

Porphyritic Basalt (with plagioclase phenocrysts)

Quartz Geode Fragment (Silicon Dioxide (SiO2)) — mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

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

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Yellow Chalcedony (Silicon Dioxide (SiO2)) — mineral

Yellow Chalcedony

Silicon Dioxide (SiO2)

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

Quartz Pebble (Milky Quartz)

Silicon Dioxide (SiO2)

Basalt with Quartz/Zeolite Inclusions (Porphyritic Basalt (SiO2 with Aluminosilicates)) — igneous

Basalt with Quartz/Zeolite Inclusions

Porphyritic Basalt (SiO2 with Aluminosilicates)

Orthoclase Feldspar (Orthoclase (KAlSi3O8)) — mineral

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Black Obsidian (Volcanic Glass (Amorphous Silicon Dioxide, SiO2)) — igneous

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide, SiO2)

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

Diorite (Salt and Pepper Rock)

Diorite

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

Diorite (Salt and Pepper Rock)

Diorite

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

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Jasper (Iron-stained Quartz) (Silicon dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Iron-stained Quartz)

Silicon dioxide (SiO2) with iron oxide inclusions

Orthoclase Feldspar (Twinning Specimen) (Orthoclase (KAlSi3O8)) — mineral

Orthoclase Feldspar (Twinning Specimen)

Orthoclase (KAlSi3O8)

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

Amethyst (Quartz)

SiO2 (Silicon Dioxide)

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

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Basalt (Basalt) — Igneous

Basalt

Basalt

Snowflake Obsidian (Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

Vesicular Basalt (commonly mistaken for Slag) (Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)) — igneous

Vesicular Basalt (commonly mistaken for Slag)

Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)

Basalt (Vesicular) (Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene) — igneous

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

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

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Mahogany Obsidian (Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Jasper Agate (Silicon dioxide (SiO2)) — mineral

Jasper Agate

Silicon dioxide (SiO2)

Nuummite (Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)) — metamorphic

Nuummite

Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)

River Pebble (Gabbro or Basalt) (Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)) — igneous

River Pebble (Gabbro or Basalt)

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

Quartz with Chalcopyrite and Pyrite (Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)) — mineral

Quartz with Chalcopyrite and Pyrite

Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)

Orthoclase Feldspar (Potassium Aluminum Silicate (KAlSi3O8)) — mineral

Orthoclase Feldspar

Potassium Aluminum Silicate (KAlSi3O8)

Snowflake Obsidian (Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Agate (Silicon Dioxide (SiO2) - variety of Chalcedony) — mineral

Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

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

Quartz (Milky/Clear Quartz)

Silicon Dioxide (SiO2)

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Smoky Quartz Cluster (Smoky Quartz (Silicon Dioxide - SiO2)) — mineral

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Black Obsidian and Hematite (Volcanic Glass (SiO2) and Hematite (Fe2O3)) — igneous and mineral

Black Obsidian and Hematite

Volcanic Glass (SiO2) and Hematite (Fe2O3)

igneous and mineral