RT Journal Article SR Electronic T1 Effect of the mutual replacement of manganese and iron on the optical properties of lithiophilite and triphylite JF American Journal of Science JO Am J Sci FD American Journal of Science SP 387 OP 390 DO 10.2475/ajs.s3-50.299.387 VO s3-50 IS 299 A1 Penfield, Samuel Lewis A1 Pratt, J. H. YR 1895 UL http://www.ajsonline.org/content/s3-50/299/387.abstract AB