Localities of Minerals. 241 
contrasted with the white, stony matrix, (principally quartz and 
sulphate of barytes) in which it is enveloped, it forms elegant 
specimens. 
Scintillating Limestone.—In Vermont, a singular scintillating 
limestone is found, of which an account is given in the following 
extract of a letter from Mr. George Chase, dated Randolph, 
February 19, 1818. 
_ “The object of the present letter is to acquaint you with a 
circumstance relating to the limestone that abounds in this pri- 
mitive country, which to me is inexplicable. This carbonate 
of lime is of a pale sky-blue colour; effervesces strongly with 
nitric acid ; and, by burning, orediaan lime, so that there is no 
question as ‘i’ the identity of the mineral. But it likewise gives 
forth sparks with steel:—this I concluded at first, to be an ac- 
cidental circumstance ; but every specimen that I have tried, 
from various quarters of the country, uniformly gives fire with 
steel. The limestone is found in layers, in blocks, and masses, 
disseminated among the clay-slate that covers the greatest part 
of the townships in this vicinity. When first taken from the 
earth, and exposed to the air, it is covered with an incrustation 
of a dark reddish-brown color, that crumbles easily between 
ihe fingers, and is generally from one inch to a foot in thickness. 
This incrustation, however, hardens on a long exposure to the 
air. This led me to think that the incrustation was owing to 
the decomposition of the limestone, which was produced by the 
sulphuret .of iron, intimately disseminated through the rock, 
Which would also explain the singular circumstance of its strik- 
ing fire. But on dissolving a small quantity of the mineral in 
nitric acid, and adding a drop or two of the decoction of gallnut, 
4 discolouring of the liquor was produced.” 
Limpid Quartz.—West Canada Creek, a northern branch of 
the: Mohawk, affords, in its sands, small crystals of quartz, lim- 
Pid, and terminated at both ends by pyramids of six sides ; we 
are indebted for specimens to Professor Fisher. 
‘etid Primitive Limestone, &c.—From the vicinity of Wil- 
ee — through the kindness of Professor Dewey, we 
No. 3. 5 
