RT Journal Article SR Electronic T1 Note on the constitution of ptilolite and mordenite JF American Journal of Science JO Am J Sci FD American Journal of Science SP 101 OP 102 DO 10.2475/ajs.s3-44.260.101 VO s3-44 IS 260 A1 F. W. Clarke YR 1892 UL http://www.ajsonline.org/content/s3-44/260/101.abstract AB