Baltic brown

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The Finnish Rapakiwigranite Baltic Brown (Vyborgite type)

Baltic Brown is a granite that is quarried on the Finnish southeast coast on the border with Russia in the province of Hamina near Ylämaa , which was incorporated into Lappeenranta in 2010 , and Husu . This natural stone was only offered on the world market from 1970. Baltic Braun was formed 1.2 billion years ago in the Precambrian .

Names

The name Baltik Braun is based on the Baltic States , a geographical and historical area on the east coast of the Baltic Sea south of the Gulf of Finland , in which the rock is located and extends as far as Russia .

Geology, rock description and mineral inventory

Main article : → Rapakiwi

Baltic Brown originated in the Precambrian when plutons penetrated the lower earth crust in the Baltic States and crystallized out over millions of years, forming large feldspar crystals . In the rock science sense, Baltic Brown is a vyborgite in which coarse-grained alkali feldspar sparrows ( orthoclase or microcline ) crystallized out, reaching a size of 20 to 50 mm. These are surrounded by one or, more rarely, several parallel lines of oligoclase . The fine-grained fringes contain quartz , biotite , hornblende and plagioclase .

Baltic Brown is one of the Rapakiwi granites, which are represented by large, round brownish large crystals. The mineral crystals are randomly distributed throughout the rock, in which biotite is almost always embedded. Baltic brown comes in different shades of brown from dark to light brown and can be delivered accordingly.

Dismantling and use

In 1970 a quarry was opened for Baltic Braun , which is still in operation today.

Regionally, Baltic Braun can be found in the architecture of southern Finnish cities and in the Saint Petersburg region . This granite has only been exported worldwide for facade design since 1970. In Germany it was first used as a grave stone, later mainly for large facades in urban planning. But it is also available for floor coverings, stairs, kitchen worktops and washbasins .

Baltik Braun is frost-resistant and can be polished.

See also

Individual evidence

  1. ^ Friedrich Müller: INSK compact. The international natural stone index for the current market . Sheet 19.3. Ebner Verlag, Ulm 1977
  2. ↑ finska.gsf.fi : Quarries and quality information , in English, accessed on May 15, 2011
  3. ↑ finska.gsf.fi : 100 Years of Granite - 1900-2000 , in English, accessed on May 15, 2011