330 Notice of Topaz and Phenakite. 
rived from the rhomboid, in addition to which also, it has the lus- 
tre, transparency, and color of quartz. In chemical composition 
however, it is more nearly related to the beryl, being a bisilicate of 
glucina. 
My first knowledge of the American mineral which If take to 
be Phenakite, was acquired about fourteen years ago, during a 
visit to the tourmaline locality in Goshen, (on the farm of Mr. 
Weeks, ) in company with Mr. Nurraux and the late Dr. Hunt of 
Northampton. My first impression was, that it belonged to iolite,* 
an opinion I afterwards changed in favor of the species beryl,t 
under which name, I believe, it has generally passed in cabinets 
ever since.{ Prof. Hrrcncock, in his Report on the Geological 
survey of Massachusetts, (p. 506, Ist edit.,) undoubtedly refers to 
the same substance, when he says, “ Beryls are frequently met 
with in our granite, though in general they are not very delicate. 
Perhaps the most so is a limpid, large beryl, occurring in Goshen, 
along with spodumene, &c. It is rare to find it distinctly erys- 
tallized, and it is full of fissures. Sometimes it is of a light rose 
color. (Nos. 1525 to 1528.)” Nor can there be the slightest ques- 
tion that the “ ‘ rose-colored emerald” alluded to by Col. Gress,$ 
as furnished him from Goshen, pertains to the species under con- 
sideration 
It occurs in considerable plenty, distributed through the pe 
in small crystalline masses, from the size of a pea to a hazel-nut, 
generally oval in form, and rarely in short hexagonal prisms, some 
of which present one face or more of the primary rhomboid, in 
the absence of their alternate angles. Other masses are round 
and offer occasionally a few roughened faces, which probably 
pertain to the primary or to a secondary rhomboid. |The prevail- 
ing color is a pale bluish white, though sometimes a faint rose- 
colored tinge is observable, eapecially:i in the well-formed hexago- 
nal prisms. Lustre vitreous; transparent to translucent only 0 
the edges. When perfectly transparent, it is a very handsome 
gem, much resembling the euclase, and like that mineral, is filled 
with fissures, and very fragile, though wanting in its brilliant 
cleavage. Hardness=7.5, being barely adequate to scratch quartz. 
tee ge Ea 
. ™ Boston Journal, vol. 13, t Idem, p. 607. 
t It should be remarked moreover, that it was =ahaved by some collectors for @ 
to topaz. 
§ Vol. 1, p. 351 of this Jour: al. 
