Is Obsidian mafic felsic or intermediate?
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. Furthermore, is Obsidian mafic or felsic?Though obsidian is…
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. Furthermore, is Obsidian mafic or felsic?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 obsidian’s composition include granite and rhyolite.Also, what does felsic intermediate and mafic mean? Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite). There is little or no quartz. Felsic rocks are mostly feldspar (especially K-feldspar), at least 10% quartz, and less than 15% mafic minerals (biotite, hornblende). Secondly, is granite mafic felsic or intermediate? Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite isIs pumice felsic or mafic?Pumice is usually felsic, but no strict chemical definition exists. Pumice can be rhyolitic, dacitic, phonolitic, etc. It just needs to be very porous and light-weight lava froth and yet it is still considered to be a rock type. These rocks have several similarities.
