MINERALOGICAL MAGAZINE JOURNAL OF THE MINERALOGICAL SOCIETY

• Main Authors: R. A. Citalmers, B. Sc, Ph D, V. C. Farmer, Ph. D, R. I. Harker, S. Kellr, M. Sc, H. F. W. Taylon, D. Sc. Ph D
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1963
• Subjects: Cornu; Greenland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.607.8822; http://www.minersoc.org/pages/Archive-MM/Volume_33/33-265-821.pdf

Summary. Reyerite from the original locality in Greenland has been re-examined using chemical analysis, infra-red absorption, X-ray powder and single-crystal diffraction, and thermal weight-loss curves. The unit cell is trigonal with a 9.74, c 19.04 A, and the space group is probably P3. The unit cell contents are probably best represented asKCa~4(Si~4Oso)(Ott}5.5H20, with some minor replacements. The molecular water is lost reversibly below 400 ~ C. There are indications that the crystal structure is based on Si60~s rings resembling those in beryl, but linked into sheets by additional tetrahedra. Reyerite closely resembles truscottite, a mineral found originally in Sumatra, but there are distinct differences, especially in the infra-red pattern. It is not yet certain whether or not the two minerals hould be considered as distinct species. Synthetic preparations examined resembled truscottite more closely than reyerite. EYERITE is a calcium silicate mineral of micaceous appearance. The original specimen was collected at Niakornak, Greenland, by Giesecke in 1811, and was first studied by Cornu and Himmelbauer