398 



Scientific Geology. 



in Ware. And I can have no doubt that any part of the gneiss 

 range, where pyrites is decomposing, will produce it. It may be 

 hoped that a fair trial will erelong be made to obtain this sub- 

 stance. This is not the proper place to make suggestions as to the 

 best mode of proceeding. Suffice it to say, that no effort should be 

 made on a large scale, without consulting some practical chemist. 



The Worcester county gneiss ranges contain in many places, an 

 abundance of blood red, often ruby red, and translucent garnets. 

 Often they are extremely minute and perfectly crystalized ; but some- 

 times, as in Brookfield, they are more than half an inch in diameter, 

 and the crystal is very imperfect. At length it becomes perfect py- 

 rope. And it is a curious fact that there is a strip of gneiss, (some- 

 times approximating to mica slate,) extending from Norwich in Con- 

 necticut, half across, and probably entirely across, Massachusetss, which 

 abounds in this mineral. This strip passes along the western part of 

 Wales, Brimfield, Ware, &c. In no place, however, except Brimfield, 

 is the color of this garnet so delicate as in Norwich, Ct. where it is 

 found in mica slate. 



The foliated masses of feldspar in the porphyritic gneiss passing 

 through Brimfield, Ware, &c. are frequently a delicate adularia. In 

 Southbridge, in a decomposing ledge of gneiss, near the center of the 

 place, the feldspar is of a delicate green, yet almost transparent ; be- 

 ing quite elegant when polished. (No. 1086.) In cavities in the 

 gneiss in Boxborough, I found distinct yetnot handsome crystals of feld- 

 spar. The same occur with actynolite, augite, and sphene, in Pelham. 



Common schorl is frequently seen in the gneiss of Massachusetts, 

 as in Athol, Pelham, and New Braintree. In the latter place, the 

 crystals have distinct acuminations. Often, as in Athol and Pelham, 

 epidote, sometimes in crystals, is associated with the schorl. 



In the New Bedford gneiss, as I was informed by T. A. Greene 

 Esq. epidote occurs along with the red oxide of titanium. In the 

 gneiss in Pelham, I have noticed some crystals of sphene as just 

 mentioned. But the sphene which I lately found in the augitic gneiss 

 in the east part of Lee, is finer than any I have met with in New Eng- 

 land. (No. 1091.) The crystals are very oblique rhombic prisms, 

 variously modified at their extremities ; resembling those represented 

 on Plate XII, figs. 47, 48, and 49 of Beudant's Mineralogy. 



It has already been repeatedly stated, that the sulphuret of iron is 

 one of the most abundant of the minerals in the gneiss of Worcester 

 county. In Hubbardston, as I have mentioned elsewhere, this ore is 



