Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)
Porphyritic Basalt (Mafic Extrusive)
Category
Browse sedimentary or igneous specimens identified by the Rock Identifier community.
Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)
Porphyritic Basalt (Mafic Extrusive)
Basalt with Quartz/Feldspar Inclusion
Basalt (containing Silicate minerals such as SiO2 and (Ca,Na)(Al,Si)4O8)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily SiO2, Al2O3, FeO, MgO, CaO)
Obsidian
Volcanic Glass (SiO2 rich)
Porphyritic Basalt
Porphyritic Basalt (with plagioclase phenocrysts)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Chondrite Meteorite
Stony Meteorite (Chondrite)
Porphyritic Rhyolite
Porphyritic Rhyolite
Obsidian
Obsidian (Volcanic Glass)
Pumice
Pumice (Alveolar Rhyolite / Dacite / Andesite)
Basalt with Quartz/Calcite Inclusions
Mafic Volcanic Rock (Fe-Mg silicate rich)
Pumice
Pumicite
Basalt with vesicles (Amygdaloidal Basalt)
Amygdaloidal Basalt (predominantly Plagioclase and Pyroxene)
Tektite (Indochinite)
Tektite (Amorphous silica-rich impact glass)
Pegmatite with Muscovite
Granitic Pegmatite (KAl2(AlSi3O10)(OH)2)
Granite
Phaneritic Granitoid (Primary minerals: Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)
Granite (Thin Section)
Granite (Felsic Plutonic Rock)
Diorite (Salt and Pepper Rock)
Diorite
Obsidian
Obsidian (Extrusive Volcanic Glass)
Porphyry
Porphyritic Rhyolite or Andesite
Porphyritic Rhyolite
Porphyritic Rhyolite (compositionally similar to granite)
Basalt (Polished River Stone)
Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)
Pumice
Vesicular volcanic glass (primarily SiO2)
Graphic Granite
Graphic Granite (variety of Pegmatite)
Basalt with Quartz Veins
Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (Amorphous SiO2 + SiO2 inclusions)
Basalt (Weathered/River worn)
Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
Granodiorite
Granodiorite (containing quartz, plagioclase, and biotite/hornblende)
Granodiorite
Phaneritic Plutonic Granodiorite
Basalt River Pebble
Mafic volcanic rock (Basalt)
Obsidian
Obsidian (volcanic glass), predominantly amorphous SiO₂
Granite
Granite (Felsic Plutonic Rock)
Granodiorite
Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)
Quartz with Mica inclusion
Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions
Scoria
Scoria (Vesicular Basaltic Glass)
Basalt
Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)
Apache Tear
Obsidian (Hydrated Silica / Amorphous Volcanic Glass)
Basalt
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
Feldspar Rich Granite with Limonite Staining
K-Feldspar Granite (KAlSi3O8)
Porphyritic Basalt with Quartz Inclusions
Aphanitic Porphyritic Basalt
Basalt
Basalt (Mafic Extrusive)