Orthopyroxene can be found in one type of these minerals heavy in silica, known as Tholeiite ("TOL-a
Orthopyroxene can be found in one type of these minerals heavy in silica, known as Tholeiite ("TOL-a-ite"). A lava with "ropy", "shelly" and "slabby" varieties is primarily composed of this mineral. Found in lavas such as a'a ("aah-aah") and pahoehoe, this type of rock is also the predominant mineral found on dark plains on the moon, known as the lunar mares. Along with chemically equivalent gabbro, this mineral is formed in spreading centers at mid-ocean ridges. This rock is less than 20 percent quartz by volume, differentiating it from granite. For 10 points, name this igneous rock which makes up the bulk of the oceanic crust.
Orthopyroxene can be found in one type of these minerals heavy in silica, known as Tholeiite ("TOL-a-ite").
basalt 