Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
igneous
Category
Igneous Rock (Volcanic Glass)
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Learn about Igneous Rock (Volcanic Glass) in the encyclopedia
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Basalt
Extrusive igneous rock
igneous
Basalt Pebble
Extrusive igneous rock
igneous
Basalt with Olivine Phenocrysts
Extrusive Igneous Rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Basalt
Extrusive Igneous Rock
igneous
Polished dark gray stone, likely basalt or andesite
Fine-grained mafic volcanic rock, commonly basalt (plagioclase ± pyroxene, olivine, and iron oxides)
igneous
Vesicular volcanic rock, likely pumice or scoriaceous rhyolite
Pumice/scoria; predominantly silica-rich volcanic glass with feldspar and quartz crystallites
igneous
Possibly tumbled dark stone or mineral specimen
Indeterminate from image; possibly black tourmaline, basalt, or another dark silicate
mineral
Obsidian (Arrowhead Lithic Tool)
Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)
igneous
Tumbled rhyolite (likely)
Rhyolite, a felsic volcanic rock composed mainly of quartz and alkali feldspar, with biotite or hornblende
igneous
Basalt
Mafic extrusive igneous rock
igneous
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
igneous
Vesicular volcanic rock, likely pumice or scoria
Pumice/scoria; predominantly silica-rich volcanic glass with feldspar and possible quartz or mafic minerals
igneous
Basalt Pebble
Extrusive igneous rock
igneous
Rounded volcanic rock, likely basaltic andesite
Fine- to medium-grained mafic volcanic rock; probable basalt or basaltic andesite
igneous
Weathered metamorphic rock, likely gneiss or schist
Indeterminate foliated silicate rock; commonly quartz–feldspar–mica assemblage
metamorphic
Basalt (Porphyritic Basalt)
Extrusive Igneous Rock
igneous
Vesicular basalt (likely scoria)
Basaltic volcanic rock; predominantly plagioclase, pyroxene, and olivine with volcanic glass
igneous
Vesicular basalt (possibly scoriaceous basalt)
Mafic volcanic rock; primarily plagioclase, clinopyroxene, olivine, and volcanic glass
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Unidentified polished stone or mineral specimen
Indeterminate from the blurred photograph; possibly a polished pale chalcedony, quartz, or feldspar piece
mineral
Basalt Pebble
Extrusive Igneous Rock
igneous
Rounded gray river pebble, likely fine-grained basalt or andesite
Basaltic-andesitic volcanic rock; commonly plagioclase feldspar, pyroxene, and minor iron oxides
igneous
Red Scoria
Scoria (Vesicular Basalt)
igneous
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix
metamorphic
Vesicular Basalt (or Scoria)
Extrusive Igneous Rock (Mafic)
igneous
Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Polished black stone, likely basalt or dark river pebble
Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor magnetite
igneous
Basalt with Quartz Vein
Mafic volcanic rock with hydrothermal SiO2 filling
igneous
Tuff
Volcanic Tuff
igneous
Dalmatian jasper (likely orbicular rhyolite)
Silica-rich rhyolite, commonly sold as Dalmatian jasper; typically quartz, feldspar, and dark amphibole/biotite inclusions
igneous
Basalt
Extrusive Igneous Rock
igneous
Dark, coarse-grained igneous rock, likely basalt or gabbro
Basalt (fine-grained) or gabbro (coarse-grained), composed mainly of plagioclase feldspar and pyroxene
igneous
Basalt
Extrusive igneous rock
igneous
Basalt
Extrusive Igneous Rock
igneous