Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/145

 Rh Viviani relates, that the lamellar metalloidal diallage, as well as the jade of Saussure, are found in the serpentine mountains of the Apennines between La Rochetta and Sassello, in eastern Liguria. It appears to form a subordinate bed in the composition of those small insulated hills, which are for the most part of serpentine, and which are scattered here and there in the great valley which separates the southern extremity of the Alps from the Apennine chain.

I was very desirous of discovering from whence came the vast quantity of blocks, consisting of diallage united with the jade of Saussure, which are met with, not only in the great valley of the Rhone, but also in that distinguished by the name of the Basin de Genéve, and I had the good fortune to discover it in 1806, in company with Mr. William Maclure, in the Visp-Klein-Thal in the Haut Valais on the skirts of Mount Rosa, which is an assemblage of mountains of serpentine. The smaragdite, or green diallage, extends here for the space of several miles, from the village of Saass (eight hundred and eleven toises above the level of the sea) ascending the Vispach, as far as the neighbourhood of Mount Moro at Macugnaga, and very near Meigeren, the most elevated village in Switzerland and the Valais which is inhabited during the whole year. This rock is found in the form of enormous rounded blocks, adhering to the ground, and heaped close together; it is sometimes only a mixture of green diallage, jade, and a little red oxide of titanium; in other places it is green diallage mixed with primitive marble; but I did not find the metalloidal variety there. Serpentine is also the matrix of the schillerspar of the Tyrol, and of that found at Baste or Paste, near Harzburg, at Mezzebergen in Moravia, &c.