• journal_title：The Canadian Mineralogist
• Contributor：John M. Hughes ; Andreas Ertl ; M. Darby Dyar ; Edward S. Grew ; Charles K. Shearer ; Martin G. Yates ; Charles V. Guidotti
• Publisher：Mineralogical Association of Canada
• Date：2000-
• Format：text/html
• Language：en
• Identifier：10.2113/gscanmin.38.4.861
• journal_abbrev：Can Mineral
• issn：0008-4476
• volume：38
• issue：4
• firstpage：861
• section：Articles

The substitution of ^[4]B for ^[4]Si in tourmaline has been the source of much discussion. A sample of olenite from Stoffhütte, Koralpe, Styria, Austria has been found to contain more than one ^[4]B per formula unit of 31 (O,OH,F), demonstrating that significant ^[4]B = ^[4]Si substitution does indeed occur in tourmaline. The composition of the structurally characterized crystal was determined using electron microprobe and SIMS data; in combination with refinement of the site scattering, the chemical data yield an optimized formula of ^Y(Na_0.400Ca_0.294□_0.306) ^Z(Al_2.424Li_0.357□_0.219) (Al_5.916□_0.084) B_3.00 (Si_4.854B_1.062Al_0.084)_{∑ 6.00} O₂₇ [F _0.06(OH)_3.31O_0.63]. The Austrian olenite crystallizes in space group R3m, a 15.731(3), c 7.0638(9) Å. The atomic arrangement was refined to R = 0.014 using X-ray data; <T–O> is equal to 1.609 Å, reflecting substitution of the smaller boron atom for Si. Conjecture on the pattern of distribution of ^[4]B can be made on the basis of X-site occupancy.