On Gabbro (Euphotide of Hauy).* By M. 

 Von BucH. Extracted by M. de Bonnarj). 



(Annales des Mines for 1816.) 



THE collection published under the name of Magazin der 

 Gesellschaft natur-forschender Freunde, zu Berlin, contains 

 (t. ly. Berlin, 1810) an interesting memoir by M. Leopold 

 von Buchj upon the rock formed of diallage, united with 

 either j^de or felspar, or with both these substances, a rock 

 to which he assigns the name of Gabbro, given it by the 

 Florentines. In the vii volume of the same collection 

 (Berlin, 1815) M. von Buch has inserted a supplementary 

 notice to his first memoir. 



The gabbro, spread over the four quarters of the world, 

 forming extensive rocks and entire mountains of several 

 thousand feet of elevation, has, until now, almost always 

 been misunderstood and confounded with other rocks, under 

 the names of granite, serpentine granite, serpentine rock, 

 and griinstein. 



Saussure was the first to make known the great quantity 

 of blocks, formed of jade and smaragdite, found on the 

 mountains of the Jura and the hills of the Pays de Vaud. 

 He was the first also to describe and class the two substances 

 of which this rock is composed, as distinct minerals. Since 

 then, M. Haiiy has united jade and felspar. Some miner- 

 alogists have thought that smaragdite or diallage ought also 



* Diallage Rock. (Trans.) 



