Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Category
Browse igneous (anthropogenic) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Apache Tear (Obsidian)
Hydrated volcanic glass (SiO2 with inclusions)
Obsidian
Volcanic Glass (SiO2, usually >70% silica content)
Sapphire (Corundum variety)
Sapphire (Al₂O₃)
Granite
Phaneritic Felsic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Basalt (Weathered Pebble)
Extrusive mafic igneous rock; minerals primarily Plagioclase feldspar and Pyroxene
Granite
Phaneritic Plutonic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Basalt with Quartz Veining
Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins
Red Granite
Phaneritic Felsic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Pumice
Pumice (Highly vesicular felsic extrusive igneous rock; primarily SiO2)
Vesicular Basalt
Extrusive Mafic Igneous Rock (composed of Plagioclase feldspar, Pyroxene, and Olivine)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Granite
Phaneritic Felsic Igneous Rock (composed primarily of Quartz and Alkali Feldspar)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
Granite
Phaneritic Intrusive Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Diorite (Salt and Pepper Rock)
Phaneritic plutonic igneous rock (sodium-rich plagioclase feldspar and hornblende)
Granite
Phaneritic Acidic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Carnelian Agate
Red Chalcedony (SiO2 with Iron Oxide impurities)
Green Quartz (Prasiolite/Adventurine)
Silicon Dioxide (SiO2) with inclusions
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Amethyst and Peridot
Amethyst (SiO2 with iron impurities) and Peridot ((Mg, Fe)2SiO4)
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) containing iron impurities
Dragon Blood Jasper (Lizard Stone/Septarian Chalcedony)
Epidote with Black Hornblende and White Quartz mixture
Citrine Quartz
Silicon Dioxide (SiO2) with ferric iron impurities
Greenschist
Chlorite schist
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Muscovite Mica (on Quartz Matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
Carnelian Agate
Chalcedony (SiO2) with iron oxide inclusions
Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Orange Calcite
Calcium Carbonate (CaCO3)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)