An igneous rock that contains mostly pyroxene and olivine has a what composition

Peridotite consists of pyroxene and olivine.

Explanation:

The igneous rock that has proxies and olivines is ultramafic in character and rock s rich in 45% of silica, showing high proportions of magnesium-rich olivine. Being a dominant rock of the upper part of the mantel.  Olivine is magnesium and pyroxenes are chains of silicates. These are related to ultra magic rocks as their mineral composition is of   plagioclase, spinel and the garnet.

Answerdistinguish between the mercalli scale and the richter scale;