Popular

Is olivine a pyroxene?

Is olivine a pyroxene?

The upper mantle of Earth is composed mainly of olivine and pyroxene minerals. Pyroxene and feldspar are the major minerals in basalt, andesite, and gabbro rocks.

What rock contains olivine and pyroxene?

Mafic
Mafic: rocks that contain mostly pyroxenes and olivine plus plagioclase feldspar and/or feldspathoid minerals, eg. basalt.

What makes olivine and pyroxene mafic?

mafic rock, in geology, igneous rock that is dominated by the silicates pyroxene, amphibole, olivine, and mica. These minerals are high in magnesium and ferric oxides, and their presence gives mafic rock its characteristic dark colour.

What are 2 intrusive rocks containing pyroxene and olivine?

So mafic rocks such as basalt or gabbro commonly contain olivine, pyroxene and Ca-rich plagioclase. Felsic rocks such as rhyolite or granite are generally rich in K-feldspar and quartz. And, intermediate composition rocks may contain pyroxene, amphibole, or biotite with plagioclase.

What colour is pyroxene?

Identification: Pyroxenes typically occur as stubby prismatic crystals. They are generally dark green to black in colour, though they can range from apple-green and lilac to colourless, depending on their chemical composition. Pyroxenes have a hardness between 5 and 7.

How can you distinguish pyroxene from amphibole?

The key difference between pyroxene and amphibole is that the pyroxene is a form of inosilicate, which contains single chains of SiO3 tetrahedra whereas the amphibole is a form of inosilicate, which contains double chain SiO4 tetrahedra.

What is the difference between peridotite and olivine?

Peridotite contains at least 40 percent olivine and some pyroxene. Unlike the olivine grains, the pyroxene grains in peridotite have a visible cleavage when viewed under a hand lens. Peridotite forms much of Earth’s mantle and can occur as nodules that are brought up from the mantle by kimberlite or basalt magmas.

What is meant by olivine?

Definition of olivine : a usually greenish mineral that is a complex silicate of magnesium and iron used especially in refractories — compare peridot.

How is olivine different from amphibole?

The most common amphibole is hornblende. It has a transparent appearance and a glassy gloss. It has very long and thin crystals. Olivine is a silicate mineral with a general chemical composition of (Mg, Fe)2 SO4, however, magnesium and iron can be replaced with calcium, manganese, and nickel.

Is olivine extrusive or intrusive?

Image Descriptions

Igneous Rocks Felsic Intermediate
Pyroxene 0% 0 to 20%
Olivine 0% 0%
Intrusive Granite Diorite
Extrusive Rhyolite Andesite

What rock has plagioclase feldspar?

igneous rocks
Members of the plagioclase group are the most common rock-forming minerals. They are important to dominant minerals in most igneous rocks of the Earth’s crust. They are major constituents in a wide range of intrusive and extrusive igneous rocks including granite, diorite, gabbro, rhyolite, andesite, and basalt.