M. Vojj Bucn an Gabbro.' 45;, 



frequently been worked by thein. Antique columns formed 

 of this rock, have, in modern times, been transformed into 

 vases, which ornament the Vatican Museum, and it is pro- 

 bable that the masses from which these columns were taken, 

 came from Egypt, as did the ancient granites and porphyries. 

 M. Werner possesses in his collection pieces of schiller spar, 

 (diallage mefalloide) with felspar, found by Mr. Hawkins 

 near Famagusta, in Cyprus, who states that the celebrated 

 copper mines worked by the ancients at Cyprus, were in a 

 rock of this nature. 



Gabbro is common in Tuscany. Targloni Tozzetti classes 

 and describes several varieties of it, which he names Nero 

 di Prato, Verde di Prato, Granito dell' Impruneta, and 

 Granito di Gabbro. The two first varieties are rocks having 

 a. serpentine base, mixed with schiller spar (diallage metal- 

 loide) ; the two others are formed of yellowish white felspar, 

 and of greenish grey schiller spar with a little jade. A 

 fifth variety is a serpentine rock resembling those of Saxony. 

 Targioni mentions numerous situations where these rocks 

 are found in the environs of Florence and Leghorn ; but 

 neither the mountains of Prato, nor those of Leghorn, have 

 been visited by modern geologists. The old observations of 

 Targioni shew how much our gabbro is united to serpentine, 

 and how much they agree in position, since he calls them 

 both by the name of gabbro. 



The rocks of Covigliano and of Pietramala arc formed of 

 gabbro, the principal mass of which is composed of diallage 

 in small grains, of a leek green colour; it contains grey 

 felspar in small grains, a great quantity of white specks, 

 which appear to be steatite, small bundles of actynolite, 

 brilliant points of pyrites, many small veins filled with cal- 

 careous spar, and geodes covered in the interior by trans- 

 parent double-pointed rock crystals ; black masses are also 

 observable, apparently of serpentine, which seem clearly ta 

 shew the passage of gabbro into that rock. 



Gabbro occurs also abundantly in the environs of Genoa; 

 the high mountains separating the gulf of Spezzia from Mont 

 Ferrat, appear to be almost entirely composed of it. Dr. 



