Obsidian
Obsidian (Volcanic Glass)
Category
Browse igneous (anthropogenic) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Unknown Rock Specimen
Granodiorite
Granodiorite (Na,Ca)(Al,Si)4O8
Bumblebee Jasper
Hydrothermal Volcanic Rock (Primarily Calcite with Orpiment - As2S3, Realgar, and Pyrite)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Granite
Granite
Basalt with Quartz/Calcite Vein
Amygdaloidal Basalt (matrix) with Mineral Vein filling
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Basalt with Mineral Vein (Cobble)
Basalt (with likely Quartz/Calcite vein)
Obsidian
Obsidian (principally SiO2/Silicon dioxide)
Limonite-stained Granite
Felsic Plutonic Rock with Hydrated Iron Oxides
Apache Tear
Obsidian (Volcanic Glass), SiO2 + MgO, Fe3O4
Basalt with Scoria
Amygdaloidal Basalt / Vesicular Basalt
Kimberlite with Diamond
Kimberlite (Porphyritic Peridotite)
Coarse-grained Granite
Phaneritic Granite (contains Quartz, Feldspar, and Mica)
Basalt
Basalt (composition of plagioclase feldspar, pyroxene, and olivine)
Kimberlite
Kimberlite (Porphyritic Peridotite)
Granite
Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)
Vesicular Basalt (Lava Rock)
Basalt with vesicular texture
Granite
Granite (composition of Quartz, Feldspar, and Mica)
Basalt
Basalt (Mafic volcanic rock)
Granodiorite (containing Biotite and Quartz)
Granodiorite (Plagioclase-rich phaneritic intrusive rock)
Granite Thin Section
Granitic rock (Phaneritic texture)
Obsidian
Volcanic Glass (mostly SiO2)
Snowflake Obsidian
Volcanic glass with Phenocrysts (SiO2 with Cristobalite inclusions)
Vesicular Basalt (Scoria)
Vesicular Basalt
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
Chondrite Meteorite
Ordinary Chondrite (L or H type)
Basalt
Basalt (Mafic volcanic rock)
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
Granite
Granite (Alkali-feldspar, Quartz, and Plagioclase composition)
Granite Tile (Commercial Granite)
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Banded Rhyolite (likely Green Jasper/Agate variety)
Silicon Dioxide (SiO2) with mineral inclusions
Basalt with Olivine Phenocrysts
Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)
Flowerstone (Porphyry)
Porphyritic Andesite or Basalt
Obsidian
Volcanic Glass (predominantly SiO2)
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt (principally composed of pyroxene and plagioclase feldspar)
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
Pumice
Pumice (a highly vesicular volcanic rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)