Iceland spar and optical fluorite

Author:	Hughes, H. Herbert
Year:	1931
Document Type:	MAIN
SUDOC:	I 28.27:6468
Series:	Information circular / Dept. of Commerce, U.S. Bureau of Mines ;
Report Number:	6468
Subjects:	Fluorspar
	Iceland spar
Link:	https://hdl.handle.net/2027/mdp.39015095079011