or Saussurite-smaragdite Gabbro of the Saasthal. 243 



from enclosures, but it occasionally contains a few granules 

 of opacite, or a grain or a cluster of granules of the honey- 

 brown mineral described below. In one specimen the edges 

 of the crystals are sometimes fringed with a rather fibrous, 

 distinctly green hornblende, indicating a change to which 

 attention has often been called by writers on glaucophane- 

 rocks. 



The garnets, where they occur (they are present in both 

 the above-named specimens containing glaucophane), are 

 sometimes roundish grains, sometimes fairly idiomorphic*, a 

 pale straw-colour with a tinge of red, often so full of enclo- 

 sures as to have a " dusty " aspect, but sometimes with clear 

 parts. Some of these enclosures resemble films, and are 

 doubly refracting, being possibly one of the constituents of 

 the " saussurite." In one of the specimens the garnets are 

 arranged in a kind of ring about the patches of glaucophane ; 

 the latter, however, occasionally interposes between them and 

 the " saussurite" (fig. 1). This ring-like arrangement of the 

 garnets is perceptible in the hand-specimen f. 



Fig. 1. (X 15. The garnet is shaded obliquely.) 



Lastly, in both these specimens, and less abundantly in 

 some of the others, we find a mineral, which occurs in grains 

 and sometimes in prisms of a rich honey-brown, darkened in 

 parts so as to become locally almost opaque. Very possibly 



* In one case the arrangement suggests that a larger grain has been 

 broken up. 



t Collected from a boulder between Zmeiden and the base of the 

 Hochlaub glacier. 



