1891.] NEW YOEK ACADEMY OF SCIENCES. 51 



three feet in width. The mica of the granite was muscovite, 

 often in imperfect crystals seven inches across and as much in 

 thickness. The smoky quartz and orthoclase occurred in cor- 

 respondingly large masses, the orthoclase sometimes being 

 crystallized. 



The garnets were most plentiful at the junction of these two 

 minerals, usually upon a face of an orthoclase crystal. The 

 garnet faces in the orthoclase were generally flattened, as the 

 numerous shallow casts on the specimens here indicate. Crys- 

 tals from the smoky quartz were fewer, but mucli lighter in color 

 and more translucent. Some of the groups are very beautiful. 

 One consists of fifty-nine crystals about three-eighths of an inch 

 in diameter, and nearly as many more casts, on a part of an ortho- 

 clase crystal ten by eight by four inches. 



An interesting feature of the garnets was their crystalline 

 form. They were the combination of the trapezohedron trun- 

 cating the rhombic dodecahedron, the faces of each being about 

 equally prominent. The largest crystal was one and a quarter 

 inches in axial diameter. Few were less than one-quarter of an 

 inch. One specimen on the table shows faces of the hexocta- 

 hedron, in addition to those before mentioned, thus giving the 

 crystal the appearance of rounded edges. 



As the blasting continued the character of the granite changed. 

 The muscovite was smaller, and oligoclase in masses nearly as 

 large as the orthoclase became common. The garnets were 

 scarcer, and their crystalline form was generally the unmodified 

 trapezohedron. To my knowledge no simple dodecahedrons 

 were found. 



The blasting was shortly discontinued, and was only recom- 

 menced a short time ago. Garnets were, however, comparatively 

 few and imperfectly crystallized trapezohedrons. While search- 

 ing, with the hope that some good garnets might still remain, a 

 half-inch beryl was found, and shortly afterward a large jointed 

 crystal in all some ten inches long. It was impossible to get 

 this crystal out whole. The best piece is upon the table. The 

 crystal was intersected at the joints by seams of quartz, remind- 

 ing one of many tourmaline crystals of this city. Although not 

 clear or colored enough to be called emeralds, fractures and 

 splinters show them to be quite glassy and translucent. 



Besides the minerals already mentioned, some tourmaline and 

 a small black crystal in orthoclase, possibly columbite, have been 

 taken from this vein. 



I am inclined to think the vein metamorphic in its origin, and 

 it evidently cooled slowly and with but little disturbance. 



