Williamsburgh Mineral. 175 
cially to the variety called spargelstein, or asparagus stone, 
as itis formed at Cap de Gate, in Murcia, in Spain. 
The characters which { have remarked in the Williams- 
burgh mineral, are—that it is electric by heat and friction, in- 
fusible per se, ‘put loses: its colour and becomes white ; with 
borax it apparently melts, at least the globule obtained is 
white, and transparent, and to the eye homogeneous. It 
scratches rock crystal when rubbed on a smooth surface of 
that substance, and is as easily scratched by the Haddam 
beryl, and by topaz of Brazil. The fracture of the perfect 
erystals i is both ways conchoidal; the lustre is shining a1 
vitreous in a high degree, both i in the natural surfaces and in 
the fracture. 
The crystal, whose colour is a delicate straw yellow, i 
prism of six sides, remarkably regular, with slight fongitadi- 
nal truncations of the solid lateral edges, thus giving the rudi- 
ments ofa prism of twelve sides; the sides are not striated, 
but reticularly indented, as if by the mica of the gangue. 
e specific gravity is 3.2, the theestratiieeee being at 65° Fah. 
the specific gravity of the beryl is 2.67, of chrysolite 3.4, of 
chrysoberyl 3.08, of phosphate of lime from 3.02 to 3.21. 
he Williamsburgh mineral phosphoresces in the dark; on a 
shovel heated red hot, it emits a yellowish light. 
January 1825.—Since the above notices were penned,| have 
received from Mr. Dwight, other specimens in their gangue ; 
some are massive and some crystallized, the colours are gen- 
erally shades of pale green, or greenish white; in a few in- 
stances nearly apple green. I extracted from the gangue the 
greater part of a large crystal, split nearly through the diago- 
nal diameter, which was more than an inch in length, ane at 
of the external sides was almost three-fourths of an 
the specific gravity of this piece, whose weight was 168: ms, 
is 3.43, the fracture Jess conchoidal and more approaching to 
foliated than that of the specimens described above; the 
phosphorescence was distinct and beautiful, and one end of 
the crystal was terminated, by a flat plane, at right angles to 
the sides; the other end was broken. 
Notwithstanding the points of rese Aah the 
Williamsburgh mineral and phosphate | @, it seemed dif- 
ficult to assign to that species, a substance which scratched 
quartz ; and satisfied with that trial, 1 neglected to apply the 
intof the knife. Learnin howev ver, from Dr. Porter, that 
. Nuttall is disposed to regard the Williamsburgh mineral 
oe 
