• journal_title：American Mineralogist
• Contributor：Andreas Ertl ; Gerald Giester ; Thomas Ludwig ; Hans-Peter Meyer ; George R. Rossman
• Publisher：Mineralogical Society of America
• Date：2012-
• Format：text/html
• Language：en
• Identifier：10.2138/am.2012.4060
• journal_abbrev：American Mineralogist
• issn：0003-004X
• volume：97
• issue：10
• firstpage：1591
• section：Articles

Synthetic Al- and B-rich tourmaline crystals described by London (2011) were characterized further by SIMS and new EMP analyses. These tourmalines are the first synthetic B-rich olenites characterized by single-crystal X-ray diffraction, because they are significantly larger than synthetic samples produced in the past. The average final formulas are ^X(Na_0.7□_0.3)^Y(Al_2.5Li_0.4Fe²⁺_0.1)^ZAl₆(BO₃)₃[Si_5.2B_0.5Al_0.3O₁₈]^V[(OH)_2.9O_0.1]^W[O_0.9(OH)_0.1], with a = 15.765(1), c = 7.083(1) Å, ^X(Na_0.7□ _0.3) ^Y(Al_2.5Li_0.5)^ZAl₆(BO₃)₃[Si_4.8B_0.9Al_0.3O₁₈]^V(OH)₃^W[(OH)_0.5O_0.5], with a = 15.746(1), c = 7.075(1) Å, and ^X(Na_0.6Ca_0.1□_0.3)^Y(Al_2.3Li_0.5Fe_0.2)^ZAl₆(BO₃)₃[Si_4.7B_1.2Al_0.2O₁₈]^V(OH)₃^W[(OH)_0.9O_0.1], with a = 15.723(1), c = 7.068(1) Å. The small <T-O> distances, down to 1.599 Å, reflect relatively high amounts of ^[4]B (up to ~1.2 apfu; refinements with R = ~2%). All these samples also contain significant amounts of ^[4]Al (~0.2 apfu). A pronounced negative correlation (r² = 1.00; only three data points) between temperature during crystal growth (at a constant pressure) and ^[4]B (from refinement) in these synthetic olenites was found.