Obsidian
Obsidian (Volcanic Glass)
Category
Browse igneous (anthropogenic) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Diorite
Phaneritic Intermediate Plutonic Rock (Diorite)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)
Basalt
Basalt (Mafic volcanic rock)
Granite
Granite (composed primarily of Quartz (SiO2), Alkali Feldspar, and Plagioclase)
Pumice
Vesicular volcanic glass
Basalt (River Pebble)
Basalt
Granodiorite
Granodiorite
Obsidian
Obsidian (Volcanic Glass, SiO2 + oxide impurities)
Mahogany Obsidian
Volcanic Glass (with inclusions of Magnetite or Hematite)
Granite
Phaneritic Plutonic Rock (Granite)
Granodiorite
Granodiorite (intermediate plutonic rock)
Basalt
Basalt
Basalt Riverstone
Basalt (Aphanitic Mafic Volcanic Rock)
Snowflake Obsidian
Vitreous Volcanic Rock (Amorphous Silicate), SiO2
Basalt
Basalt (Mafic Volcanic Rock)
Basalt with Scoria/Vesicular texture
Vesicular Basalt (primarily Plagioclase feldspar, Pyroxene, and Olivine)
Obsidian
Volcanic glass (no mineral formula due to amorphous structure, mostly SiO2)
Obsidian
Volcanic Glass (70% or more SiO2)
Coarse-grained Quartz with Feldspar inclusions
Crystalline Quartz (SiO2) with Orthoclase/Plagioclase Feldspar inclusions
Diorite
Diorite
Basalt with Vesicles
Vesicular Basalt
Basalt
Extrusive mafic rock (Basalt)
Obsidian
Amorphous Volcanic Glass (primarily SiO2)
Apache Tear
Obsidian (Hydrated Volcanic Glass, SiO2)
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily Plagioclase Feldspar, Pyroxene, and Olivine)
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
Yooperlite (Syenite clasts with Sodalite)
Fluorescent Sodalite-bearing Syenite
Rhyolite
Rhyolite
Vesicular Basalt with Oxidation
Scoriaceous Olivine Basalt (Mafic volcanic rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock)
Granite
Granite (Felsic Plutonic Rock)
Granite (Alkali-feldspar Granite)
Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)
Granite (with Muscovite Mica)
Phaneritic Felsic Igneous Rock (primarily Quartz SiO2, K-Feldspar KAlSi3O8, and Muscovite KAl2(AlSi3O10)(OH)2)
Chinese Writing Stone
Porphyritic Basalt or Porphyritic Andesite
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide SiO2)