Obsidian (Arrowhead Lithic Tool)
Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Obsidian (Arrowhead Lithic Tool)
Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)
Quartz Druzy (on Calcedony/Quartz base)
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic Extrusive)
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Pumice
Felsic Volcanic Glass / Vesicular Rhyolite
Pumice
Highly vesicular rhyolite/dacite (Amorphous glass)
Basalt with Quartz/Zeolite Inclusions
Porphyritic Basalt (SiO2 with Aluminosilicates)
Vesicular Basalt with Lichen
Vesicular Basalt
Basalt
Basalt
Pumice
Vesicular volcanic glass (primarily SiO2)
Granite
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
Limonite-stained Granite
Felsic Plutonic Rock with Hydrated Iron Oxides
Basalt
Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)
Clear Quartz Crystal (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
Vesicular Basalt (or Porphyritic Scoria)
Vesicular Basalt
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
Porphyritic Andesite (often called Chinese Writing Stone)
Porphyritic Basaltic Andesite with Feldspar Phenocrysts
Apache Tear (Obsidian)
Obsidian (Hydrated Amorphous Silica, SiO2 + MgO/Fe3O4)
Porphyritic Basalt
Amygdaloidal Porphyritic Basalt
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
Milky Quartz
Silicon Dioxide (SiO2)
Pumice
Pumice (volcanic glass with vesicular texture)
Porphyry (Flower Stone)
Porphyritic Basalt or Andesite
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Vesicular Basalt with Oxidation
Scoriaceous Olivine Basalt (Mafic volcanic rock)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Milky Quartz (with Iron staining)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Milky Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Quartz Vein with Iron Staining
Silicon Dioxide (SiO2)
River Quartz Pitting/Cobble
Silicon Dioxide (SiO2)
Lapis Lazuli
Na8(Al6Si6O24)S2 (composed primarily of Lazurite, Calcite, and Pyrite)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Greenstone with Quartz Veining
Epidiorite or Metabasalt with SiO2 (Quartz) veins
Blue Chalcedony
Microcrystalline Quartz (SiO2)
Porphyritic Basalt
Amygdaloidal Porphyritic Basalt
Basalt (Lava Rock) and Dyed Glass/Quartz
Scoria (Vesicular Basalt)