Pegmatites are important because they often contain rare earth minerals and gemstones, such as aquamarine, tourmaline, topaz, fluorite, apatite and corundum, often along with tin and tungsten minerals, among others. ... The majority of the world's beryllium is sourced from non-gem quality beryl within pegmatite.

Why is pegmatite an economically important igneous rock?

Pegmatite is an extremely coarse-grained intrusive igneous rock composed of large interlocking crystals. ... Pegmatite is an economically-important rock because it is the source material for lithium, cesium, and rare earth elements and because it may hold large gemstones.

What is the characteristics of pegmatite?

pegmatite Very coarse-grained, igneous rock, usually of granitic composition, in which the individual crystals are at least 2.5 cm long. The crystals are often more than 1 m in length, and may be far larger. Crystallization occurs at a late stage, when the magma is enriched in volatiles and trace elements.