176 Williamsburgh Mineral. 
“as a: Rips sphate of lime, and from Mr. Dwight that it is dis- 
solved by the acids ;* T then for the first time, endeavoured to 
impress it with a knife, and found to my surprise, that all the 
varieties were oo Se by steel, with little more difficulty 
than fluor spar. 
as relate the ¢ cum istance in order to show the necessity of 
, in drawing conclusions especially from the relative 
bards of eee fora softer substance, mays by continued 
and e made to impress a har Instances 
C this kind are numerous in the arts, and in aa case of the 
pritty pbowders used in polishing hard stones. Ropes will 
wear wood and even stone; wood will wear metals, and 
metals will abrade earthy minerals; even a soft leather strap 
pol nd sharpens the hardest steel. 
disposed to think with Mr. Nuttall, ee oe Williams- 
| mineral is a phosphate of lime, an it_ phospho- 
resces, we must assign it to the variety «pate x “This i is not 
the first time oe this mineral (strongly resembling several of 
the gems eld mineralogists in doubt, as to its nature, 
and Se ‘astiGad its Greek name of the deceiver.t 
add an extract ofa letter from Mr. Dwight, dated June 
is 1824, prefacing it with the remark, that the minerals men- 
tioned by him, are all well cha racterized, a nd the plumose 
mica, and the micaceous iron (especially the latter) extremely 
heautifi I. 
“T take the liberty to send you a, box of minerals contain- 
ing the following specimens. 
- Argentine, Williamsburgh, 
. ah ag phous quartz, do. 
pi do 
a 
goto 
4, Placing mi do. 
5. Micaceous oxide of ir on, Hawle 
We have recently discovered the Grane of argentine. It» 
occurs in large masses of a superior quality—I think some 
pure masses will weigh tons. 
he quartz is found in the vicinity of the argentine. The 
dog-tooth projections appear to have formed upon the dog- 
tooth spar originally. Some of these projections however are 
rectangular ; perhaps these were formed upon crystals of sul- 
* A fact which I have since Seip tara Be <apeaent, and the dissolved 
mineral was again precipitated b 
+ From *Araraw, to deceive 
