Foyaite

Classification：Igneous Rock

A rare igneous rock, composed of alkali feldspar from nepheline and rough structure, is a kind of nepheline syenite.

Is a kind of nepheline syenite with wide distribution. It has a rough surface structure. The mineral composition is dominated by orthopystite (about 60%), followed by nepheline and a small number of other feldspar (20%~25%), and the dark minerals are mainly neon pyroxene, and sometimes hornblende, biotite or neon.

It is reddish brown, rich in iron and titanium, and is usually distributed in the periphery of pyroxene and hornblende. The accessory minerals are very abundant, most of them are silicates of Ti, Zr and Nb. There are common monoclinic zircon tantalite, monazite, anisite, garnet, calcium cerium lanthanum, silicon cerium ore, silicon cerium titanium ore, heterosexual stone and negative.