Publication Type:Journal Article
Source:Powder Diffraction, Cambridge University Press, Volume 29, Number 1, p.69-75 (2014)
Keywords:Borate minerals, deposits, diffraction, Sodium borate, X ray powder diffraction
Veatchite polytypes were properly identified from several localities relying solely on micro powder diffraction data. Diagnostic differences in their respective calculated patterns gave reliable identification results when compared with measured data. This permitted the confirmation of co-existing veatchite-1A and -2M on the same specimen from the Billie Mine, Inyo County, California as flat elongated crystals (-1A) and flat rhombic plates (-2M), respectively. On the specimen from the Sterling Borax Mine (Lang), type-locality for veatchite-2M, the polytype veatchite-1A was confirmed from radiating rhombic plates. From the type specimen for veatchite-1A (rhombic plates), collected from the borate deposit in Emet, Turkey, an additional unknown polytype of this mineral was discovered, but lacks suitable material for a complete characterization. At the Penobsquis deposit near Sussex in New Brunswick, Canada, only veatchite-2M was encountered. The area between 20 and 252 holds the following diffraction signatures: -1A (two sets of double peaks at approximately 21.5 and 24.52), -1M (single peaks at 20 and 232) and -2M (double peaks at 20 and 232). The unknown polytype from Emet, Turkey differs from polytype-1A in that same range by having single peaks at the 21.5 and 24.5instead of double peaks. 2013 International Centre for Diffraction Data.
Compilation and indexing terms, Copyright 2018 Elsevier Inc.<br/>20140917406200<br/>Borate deposits<br/>Co-existing<br/>Micropowders<br/>Phase identification<br/>Polytypes<br/>Profile fitting<br/>Single peak<br/>veatchite