Unpublished reports on open file II
Subtitle: industrial minerals
By: by Margaret B. Brophy
Series: Illinois State Geological Survey. Circular -- no. 209; Circular (Illinois State Geological Survey) -- no. 209.
Publisher: Illinois State Geological Survey
Published: 1956
Place of publication: Urbana
Language: eng
Subjects: Mineral files; Bibliography; Geology
Other titles: Industrial minerals.