MINERALOGY, 6/ 



crystals from the same localities. The form and dimensions of two of 

 these large crystals from Grafton are shown in Figs. 4 and 5 on PI. 3, which 

 represent the outlines of the bases and the dimensions in inches. The 

 measurements were made by Prof. O. P. Hubbard,* who attempted their 

 extraction, in which effort one was destroyed. The other one has since 

 been broken up and scattered abroad. These crystals are among the 

 largest that any species of mineral has ever afforded, and it is sad that 

 the best specimens should have been destroyed. Their form is as regular 

 as hexagonal crystals of smaller size will average. The crystal, the base 

 of which is represented in Fig. 4, was originally six and a quarter feet long. 

 These beryls, when of this enormous size, are apt to have subordinate 

 planes, as is shown at a in the drawing. The crystal from which Fig. 5 

 is drawn, weighed over two and a half tons. One beryl extracted from 

 the Acworth quarries is four feet long, and two and a half feet in diame- 

 ter. The one that is preserved in the rooms of the Boston Society of 

 Natural History is represented in the frontispiece, with a scale below it 

 representing its dimensions in feet. 



These large crystals are of a pale green color, and many of them have 

 been extracted, and are exhibited as great curiosities in the museums of 

 the world. Some very large crystals still remain in the quarries, where 

 they can be seen ; but their extraction is a matter of considerable expense, 

 since much rock must be moved in order to obtain them, and, moreover, 

 it is very hard to get them out whole, since the material of which beryl 

 is composed is very brittle, and filled with rifts, and a jar is sufficient to 

 break them when they are not well supported. The large crystals have 

 always been securely hooped before any attempt was made to move them. 

 Prof. Hitchcock has obtained one for the state museum, weighing half 

 a ton. 



Smaller but much more perfect and beautiful crystals are found in the 

 quarries from which these large beryls are obtained, and also in other 

 localities. They are usually terminated by a smooth basal plane, but 

 often have in addition the planes of an hexagonal pyramid, Canaan, 

 Wilmot, Springfield, Danbury, the islands of Lake Winnipiseogee, the 

 northern part of Rumney, Chatham (in the stream near the path to Bald- 

 face), Campton, New Ipswich, Sullivan, Plymouth, Wilmot, New London, 



* Hubbard, Am. J. Sci., ii, vol. xiii, p. 264. 



