WOLFF. — HARDYSTONITE. 481 



Its systematic position is perhaps not clear without crystallographic 

 material. Having an oxygen ratio of 4:3 it would belong among the 

 intermediate silicates (Dana's System, 6th ed.), and its tetragonal system 

 and cleavages would place it near ganomalite (Pb3Si20,). Some genetic 

 connection with clinohedrite * (HoCaZnSiOg) may be surmised, as both 

 minerals come from the same workings, and the writer is informed that 

 a white mineral, probably hardystonite, has been found there in con- 

 siderable quantity. It is hoped in a future visit to the mines to obtain 

 further light on these questions. 



* Penfield and Foote, Am. Journ. Sci., 1898, Vol. V. p. 289. 



VOL. XXXIV. — 31 



