Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Category
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Basalt
Mafic extrusive volcanic rock (composed primarily of Plagioclase feldspar and Pyroxene)
Basalt
Basalt (principally Plagioclase Feldspar and Pyroxene)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (SiO2)
Obsidian
Obsidian
Olivine (Peridotite)
(Mg, Fe)2SiO4 (Magnesium Iron Silicate)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Basalt Pebble
Basalt
Dalmatian Jasper
Peralkaline Feldspar Rhyolite
Basalt with Weathered Crust
Aphanitic Mafic Igneous Rock (Basalt)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Smoky/Granular variety)
Silicon Dioxide (SiO2)
Quartz with Host Rock
Silicon Dioxide (SiO2)
Basalt Column Section
Columnar Basalt (Mafic Extrusive Igneous Rock)
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Quartz
Silicon Dioxide (SiO2)
Quartz-rich gravel fragment
Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions
Basalt River Pebbles
Mafic Volcanic Rock (主要成分: SiO2, MgO, FeO)
Diabase (Dolerite)
Diabase
Granite (Background) and Quartzite/River Pebble (Foreground Heart)
Phaneritic Felsic Igneous Rock (Granite background)
Basalt
Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)
Quartz Pebble
Silicon Dioxide (SiO2)
Basalt (River Stone)
Vesicular Basalt
Dalmatian Jasper
Dalmatian Stone (a porphyritic peralkaline igneous rock)
Vesicular Basalt
Extrusive Mafic Igneous Rock (Vesicular Basalt)
Grey Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
Milky Quartz
Silicon Dioxide (SiO2)
Basalt Scoria
Aphanitic basaltic scoria
Porphyritic Basalt or Porphyry
Porphyritic Extrusive Igneous Rock
Basalt
Extrusive Mafic Igneous Rock
Basalt
Basalt (Mafic igneous rock)
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
Basalt with Iron Oxidation
Mafic Igneous Rock (Basalt)
Basalt Pebble
Basalt
Basalt with Porphyritic Texture
Porphyritic Basalt
Basalt
Basalt
Basalt with Iron Oxidation
Vesicular Basalt (Aphanitic Mafic Igneous Rock)
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)
Polished agate/chalcedony fragment
Microcrystalline quartz (SiO₂), likely banded chalcedony or agate
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)