Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
Category
Browse basalt specimens identified by the Rock Identifier community.
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
Basalt with Desert Varnish
Mafic Igneous Rock with Ferromanganese Coating
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
Limonitic Scoria (Vesicular Basalt with Iron Staining)
Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]
Scoria (Vesicular Basalt)
Scoria (Hydrated silicate volcanic rock with iron and magnesium)
Greenstone (River Pebble)
Metabasalt / Greenschist
Greenstone
Metabasalt / Chlorite Schist
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
Labradorite (a variety of Anorthosite or Plagioclase)
Labradorite (member of Plagioclase Feldspar series), (Ca,Na)(Al,Si)4O8
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Bauxite (Pisolitic Bauxite)
Bauxite (mixture of Hydrous Aluminum Oxides)
Agate (Moss or Banded Agate variety)
Agate (Silicon Dioxide - SiO2)
Agate
Chalcedony (SiO2)
Smoky Quartz and Chalcedony Geode Fragment
Silicon Dioxide (SiO2)
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
Blue Lace Agate (with Amethyst Geode center)
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
Lake Superior Agate
Chalcedony (Microcrystalline Quartz, SiO2)
Lake Superior Agate
Chalcedony (SiO2 with iron impurities)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Gray Agate
Chalcedony (Silicon Dioxide, SiO2)
Scoria
Vesicular Basaltic Glass (comprised primarily of volcanic glass/silica with plagioclase, pyroxene, and olivine crystals)
Diorite
Phaneritic Intrusive Igneous Rock (Intermediate Composition)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst Cluster
Amethyst (Silicon Dioxide), chemical formula: SiO2
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of Fe3+)
Amethyst
Silicon Dioxide (SiO2)
Scoria (Lava Rock)
Scoria
Porphyritic Basalt (Chinese Writing Stone/Flower Stone)
Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)
Banded Agate (specifically Lake Superior Agate)
Silicon Dioxide (SiO2)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Scoria (Red Lava Rock)
Scoria
Sunstone
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
Lake Superior Agate
Chalcedony (SiO2 with Iron inclusions)
Amethyst Geode
Amethyst/Purple Quartz (SiO2)
Amethyst
Amethyst (SiO2 with iron impurities)
Scoria (Lava Rock)
Scoria
Amethyst
Amethyst (variety of Quartz, SiO2)
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Epidosite (Epidote-rich rock)
Epidotalite (primarily Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH))
Banded Agate (Tumbled)
Cryptocrystalline Quartz (SiO2)