Prasinite
on the left with calcite clouds, on the right with a stronger ophiolitic structure
The prasinite (green stone ) is a fine-grained, massive metamorphic rock of the green slate facies , which is formed by the transformation of mafic rocks (basalts and chemical relatives) at medium pressures and temperatures. It is a massive one, i.e. H. unslate and isotropic , counterpart of green slate . The term is often found in older German-language literature.
As a result of the zone-like accumulation of the various main parts of the mixture ( chlorite , actinolite , albite and epidote ) it has a banded, hardly sloping appearance. It is used as a road construction material and as a decorative stone .
Examples of occurrences are Zillertal ( Austria ), Ticino , Wallis ( Switzerland ), near Bastia on Corsica and in northern Italy . The most famous summit made from Prasinit is probably the Großglockner . The natural stone from the Valais deposits ( Val d'Hérens ) became known under the trade name Vert d'Evolène . Furthermore, a Prasinit, which goes on the market with the name Prasino , is mined in Gemlik near Bursa in Turkey.
literature
- Toni P. Labhart: Geology of Switzerland . Thun (Otto Verlag) 2001 ISBN 3-7225-6762-9
- Raymond Perrier: Les roches ornementales . Ternay (Edition Pro Roc) 2004 ISBN 2-9508992-6-9
- Wolfhard Wimmenauer: Petrography of igneous and metamorphic rocks . Enke Verlag, Stuttgart 1985, ISBN 3-432-94671-6