Aluminous Pyroxenes in Metamorphosed Limestones

The name “fassaite” (Werner, 1817) was originally given to the leek- to dark-green pyroxene crystals of the Fassatal, characterized by a distinct habit with the zone [110] strongly developed. Subsequent to the analytical data of Doelter (l) on the Monzoni fassaites the name has come to be applied more generally to alkali-poor aluminous pyroxenes found in metamorphosed lime-Stones and dolomites. Doelter's analyses of the Monzoni fassaites date back as far as 1877 and are chiefly remarkable for their high alumina and ferric oxide contents.