142 Mr HAIDINGER on the Natural-Historical 



rallel to the prism (Pr + oo) 3 = 124 13'; and although com- 

 pound, in the direction of the faces of Pr+ oo, they neverthe- 

 less present but a very inferior degree of lustre, upon these 

 faces of composition, if compared with those of cleavage. The 

 colour is a dark greenish-grey, and the specific gravity 3.043. 



Besides the rocks described, there are still a great many whose 

 characteristic ingredient is said to be DiaUage, which, however, 

 do not contain any hemiprismatic Augite-spar at all, but only the 

 varieties of the paratomous. Thus, the Eclogite of HAUY, found 

 in the Saualpe in Carinthia, is a mixture of red Garnet and leek- 

 green, paratomous Augite-spar, of the variety called Omphazite 

 by WERNER. The rocks from Austria and Bayreuth, which con- 

 tain Omphazite, though smaller grained, are exactly of the same 

 composition. The variety from the Saualpe occasionally con- 

 tains small greenish-white prisms of Zoisite (prismatoidal Augite- 

 spar). 



VON BUCK has sufficiently ascertained the remarkable geo- 

 gnostic relation between Gabbro and Serpentine, in many places 

 which he visited during his travels. The Bacher in Lower 

 Stiria, gives another proof of this fact. Here the Gabbro rock 

 appears to constitute considerable masses in the Serpentine, near- 

 ly in the same way in which the masses of ore usually occur in 

 beds, or still more distinctly in metalliferous veins, if we may in- 

 dulge ourselves in considering the latter as points of comparison. 

 Yet it has not been possible to strengthen this opinion, by ob- 

 serving the immediate contact of the two rocks ; it is rather the 

 consequence of their distribution over the surface of the coun- 

 try. 



It is attended with less difficulty to determine the position of 

 the rock from the Saualpe. It constitutes a subordinate bed in the 

 gneiss, and mica-slate formation of the Alps, and has been opened 

 by a quarry situate at the southern extremity of the Saualpe, in 



