Methods and costs of mining fluorspar from a flat-bedded deposit at Cave-In-Rock, Ill.

Author:	Needham, A. B.
Year:	1949
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7514
Series:	Information circular / Bureau of Mines ;
Report Number:	7514
Subjects:	Fluorspar industry--Illinois
	Fluorspar--Illinois
Link:	https://hdl.handle.net/2027/mdp.39015078463794