I 
10 MINERALOGICAL 
Tin-ftone with wolfram is found at 
Wheal Mutterel, in Gwennap. 
Zinngraupen, both of large and middle 
fizes, in double quadrangular pyramids, 
fo as to form what is called Vijirgraupen^ 
the cryftals of which have loft fome- 
thing of their glofs and (harpnefs of an¬ 
gles are found at Bun-mine, in St. Auftle, 
in much decayed granite or growan. 
Other fpeeies of rich tin-ftones and Zinn- 
zwitter are found at Mainvrofe and Men- 
garn in Wendron, Trethallan in St. Ste¬ 
vens, and Huel Malkin. The tin-ftone 
from the latter place is formed by very 
fmall clear white grey tin cryftals, grown 
intimately together, with very fine, moftly 
greenifh particles of mica. In fome 
places the tin-ftone has fifibres, the cavi¬ 
ties of which are lined with fmall tin 
cryftals, of a garnet form; now and then 
it is run through with fmall veins of red 
jalper, and contains nodules of it. 
Stream- 
