of Serpentine, &;c. in the Apennines. 173 



size of an egg cannot be obtained. These very numerous 

 strata, all parallel to each other, are highly inclined, and 

 dip to the E.N.E. under the preceding serpentine. But it 

 has been imagined that at the point of contact of the jasper 

 and serpentine, the latter rock is altered ; it becomes whitish, 

 friable, granular, and has some appearance of an altered or 

 imperfect diallage rock. Beneath the jasper, a portion of 

 the mountain is passed over covered by vegetable soil, pas- 

 turage, and woods, which affords no opportunity of any 

 where seeing the inferior rocks exposed, or in their primitive 

 position. But large blocks of limestone (D), and even 

 heads of beds are from time to time met with ; this fiue com- 

 pact limestone, of a smoke grey colour, possesses all the 

 characters of that of Rochetta, and although I have not 

 seen it evidently beneath the jasper and serpentine, it may 

 be presumed that it is, as at Rochetta, placed under these 

 rocks ; analogy indicates it, and no observation proves the 

 contrary. 



On this side the mountain the diallage rock is wanting ; 

 but on its northern side and towards its base, though still 

 at an elevated situation, a thick mass of this beautiful rock 

 is worked, which is here very hard. It contains, besides 

 compact felspar that constitutes its base, a sublarainated 

 felspar possessing a slight violet tint, and melting before 

 the blowpipe into white enamel. Its slightly fat appear- 

 ance causes it at first sight to be taken for quartz. 



Large and good millstones are made of it. 



Descending from these quarries into the plain, we find 

 not the jasper bed, it is probably too thin, and appears io 

 have been reduced in thickness as much as the bed of ser- 

 pentine has augmented, but small fragments of jasper dis- 

 seminated in the soil, that indicate its place, and lower 

 down the fine compact limestone of a smoke grey colour.* 



* Count Bardi had remarked the position of the serpentine on the 

 jasper, and had stated it in a memoir published in the 2d volume of the 

 Memoirs of the Florence Institute, entitled, Osserv. miner, sopra alcuni 

 luoghi adjacenti alle pianura di Prato. He says, page 20 of this memoir, 

 " The gabbro (serpentine) immediately rests on the jasper, and reaches 



