Pegmatites

A gem quality beryl-bearing pegmatite in the Wiborgite Rapakivi granite batholith - A glance into the 1.63Ga old Luumäki pegmatite system.

Some of the most intriguing rock formations on planet earth are pegmatites with their often exotic assemblage of minerals in various sizes, shapes and colors. Already known in ancient Egypt for their beauty and precious gem quality, and possibly even earlier in human history, the minerals found in pegmatites are essential in today's technological advancement. The large and relatively pure feldspar and quartz found in granitic pegmatites are used in the ceramic industry and the fact that pegmatites are ideal hosts for exotic minerals enriched in elements such as Li, Be, Rb, Cs, REEs, Nb, Ta, Zr, Hf and Th, just to mention a few, makes them economically important for strategic hi-tech and rare element mining.

Ever since, geologists are puzzled about the mechanics of formation of pegmatites and their huge crystals. This project is aiming at shedding light on the petrological and geochemical processes involved in the formation of a granitic pegmatite system within the Rapakivi granite suite in Luumäki, East Finland. The Luumäki pegmatite is distinguished by hosting gem-quality beryl crystals of the greenish-yellow heliodor and bluish aquamarine variety. It is the only gem-beryl bearing pegmatite in Finland. Its high quality gem stones are used in the Kalevala Jewelery, inspired by the centennial of the Finnish national epic, the Kalevala, and is even worn by Jenni Haukio, the wife of Finland's president Sauli Niinistö.

 

People

Dipl.Min. Radoslaw M. Michallik (PI)

Prof. Thomas Wagner (Project manager, supervisor)

Prof. Tapani O. Rämö (co-supervisor)

M. Sc. Pasi Heikkilä

Ph. D. Tobias Fusswinkel

Ph.D Jussi.S. Heinonen

 

Publications

Chemical evolution and origin of the Luumäki gem beryl pegmatite: Constraints from mineral trace element chemistry and fractionation modeling. Lithos, Vol: 274, Page: 147-168

The role of magmatic and hydrothermal processes in the formation of miarolitic gem beryl from the Luumäki pegmatite, SE Finland. European Journal of Mineralogy, Vol: 31 (3), Page: 507-518