Scoria (Lava Rock)
Scoria (Extrusive Igneous Rock / Mafic Silicates)
Category
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
Scoria (Lava Rock)
Scoria (Extrusive Igneous Rock / Mafic Silicates)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity isotopes)
Dalmatian Stone
Dalmatian Stone (a peralkaline igneous rock consisting of Feldspar, Quartz, and Arfvedsonite)
Obsidian
Volcanic Glass (SiO2 dominant)
Basalt with Amygdules
Amygdaloidal Basalt
Obsidian (Apache Tear)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Gossan (Iron Hat)
Limonitic Gossan (Fe-oxide/hydroxide complex)
Larvikite
Monzonite (intermediate intrusive igneous rock containing plagioclase, alkali feldspar, and minor dark minerals)
Granite (Weathered/Oxidized)
Phaneritic Felsic Igneous Rock (composed of Quartz, Orthoclase Feldspar, and Mica)
Obsidian
Vitreous volcanic silicate (70-75% SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Jasper Agate
Silicon dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Labradorite
Labradorite (Ca,Na)(Al,Si)4O8
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide SiO2)
Black Obsidian
Volcanic Glass (SiO2 + impurities like Fe3O4)
Quartz with Tourmaline and Iron Staining
Silicon Dioxide (SiO2) with Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
Granite
Granite (composed primarily of Quartz SiO₂, Alkali Feldspar KAlSi₃O–NaAlSi₃O–CaAl₂Si₂O₈, and Plagioclase Feldspar)
Red Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily SiO2, Al2O3, FeO, MgO, CaO)
Porphyritic Basalt
Porphyritic Basalt (with plagioclase phenocrysts)
Porphyry
Porphyritic Rhyolite or Andesite
Obsidian
Volcanic Glass (Primary component: SiO2)
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Granite
Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, NaAlSi3O8)
Amygdaloidal Basalt
Amygdaloidal Basalt (with secondary mineral infilling)
Peridotite
Ultramafic intrusive rock (Peridotite)
Lava Rock (Scoria)
Scoria (Vesicular Basalt)
Granite (Leucogranite)
Felsic Plutonic Rock (Granite)
Basalt (River Cobble)
Basalt (Mafic volcanic rock)
Scoria
Vesicular Basalt / Scoriaceous Basalt
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Basalt Porphyry (River Pebble)
Porphyritic Basalt
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Sodalite Syenite (popularly known as Yooperlite)
Sodalite-rich Syenite (composed of alkali feldspar and sodalite)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and K-feldspar)
Obsidian Arrowhead
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)