Is Obsidian mafic or ultramafic?
Obsidian is volcanic glass which erupts as a lava flow. Most obsidian is felsic in composition, yet typically it will have a very dark color (dark brown to black). Dunite has an ultramafic composition yet is apple green to yellowish green in color.Click to see full answer. Similarly one may ask, is Obsidian mafic?Though obsidian…
Obsidian is volcanic glass which erupts as a lava flow. Most obsidian is felsic in composition, yet typically it will have a very dark color (dark brown to black). Dunite has an ultramafic composition yet is apple green to yellowish green in color.Click to see full answer. Similarly one may ask, is Obsidian mafic?Though obsidian is usually dark in color, similar to mafic rocks such as basalt, obsidian’s composition is extremely felsic. Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% or more. Crystalline rocks with a similar composition include granite and rhyolite.Likewise, what is felsic vs mafic vs ultramafic? In a widely accepted silica-content classification scheme, rocks with more than 65 percent silica are called felsic; those with between 55 and 65 percent silica are intermediate; those with between 45 and 55 percent silica are mafic; and those with less than 45 percent are ultramafic. Additionally, what is mafic and ultramafic? Igneous Rocks by Composition Igneous rocks are classified according to their mineral content: Ultramafic rocks are dominated by olivine and/or pyroxene. Mafic rocks are dominated by plagioclase and pyroxene (even if you can’t see them with the naked eye) and smaller amounts of olivine.What does ultramafic rocks contain? Ultramafic Rock An igneous rock with a very low silica content and rich in minerals such as hypersthene, augite, and olivine. These rocks are also known as ultrabasic rocks. Examples include: peridotite, kimberlite, lamprophyre, lamproite, dunite, and komatiite.
