Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
Category
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
Vesicular Basalt with Oxidation
Scoriaceous Olivine Basalt (Mafic volcanic rock)
Amethyst (Purple Quartz)
Silicon Dioxide (SiO2) with iron impurities
Scoria
Scoria (a vesicular basalt or andesite)
Clear Quartz
Silicon Dioxide (SiO2)
Amygdaloidal Basalt
Amygdaloidal Basalt (containing secondary minerals like Quartz, Zeolites, or Calcite)
Basalt with Jasper Veining
Basaltic Rock with Cryptocrystalline Quartz (SiO2)
Basalt
Basalt
Grey Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Basalt with Epidote Veining
Basalt (Mafic Extrusive Rock) with Ca2(Al,Fe)3(SiO4)3(OH)
Obsidian
Amorphous volcanic glass (70-75% SiO2)
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Red Quartz (Druzy)
Silicon Dioxide (SiO2) with Hematite inclusions
Granite
Granite (Felsic Plutonic Rock)
Obsidian
Obsidian (principally SiO2)
Basalt
Basalt (Fine-grained extrusive igneous rock)
Quartz (Milky/Common)
Quartz (Silicon Dioxide, SiO2)
Basalt with Magnetite
Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)
Porphyritic Basalt (or Porphyry)
Porphyritic Basalt (Mafic volcanic rock with phenocrysts)
Vesicular Basalt
Extrusive Mafic Igneous Rock (composed of Plagioclase feldspar, Pyroxene, and Olivine)
Agate (Moss or Dendritic Agate)
Chalcedony (Silicon Dioxide, SiO2)
Smoky Quartz on Feldspar (Granite Pegmatite)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)
Basalt
Basalt (Mainly Plagioclase Feldspar and Pyroxene)
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
Yooperlite (Syenite clast containing fluorescent Sodalite)
Sodalite-bearing Syenite
Milky Quartz
Silicon Dioxide (SiO2)
Pink Granite
Granite (Phaneritic intrusive igneous rock dominated by Quartz and K-Feldspar)
Banded Agate (specifically Carnelian Agate slice)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
Yellow Quartz (Citrine or Yellow Jasper)
Silicon Dioxide (SiO2)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Thunderegg (Ate Agate/Jasper Geode)
Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Diorite (River Cobble)
Intermediate Phaneritic Plutonic Rock
Amethyst
Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities
Basalt
Basalt
Porphyritic Basalt (Amygdaloidal)
Porphyritic Mafic Volcanic Rock (Amygdaloidal Basalt)