Occurrence and mineralogy of the margarite- and muscovite-bearing pseudomorphs after topaz in the Juurakko pegmatite, Orivesi, southern Finland
Margarite- and muscovite-bearing pseudomorphs after topaz are described from the Juurakko pegmatite dyke, Orivesi, southern Finland.A supercritical vapour phase rich in calcium and alkalies caused alteration of topaz and some other silicates during final phase of crystallization of Lacrosse - Balls the dyke.The original columnar form of topaz cryst