Herderite from Mogok, Myanmar, and comparison with hydroxyl-herderite from Ehrenfriedersdorf, Germany
Herderite from Mogok, Myanmar, and comparison with hydroxyl-herderite from Ehrenfriedersdorf, Germany
复制标题
产自缅甸摩谷的水硬石,以及与产自德国埃伦弗里德斯多夫的羟基水硬石的比较
DOI:
10.2138/am.2008.2943
复制
发表时间:
2008
影响因子:
3.1
通讯作者:
F. Hawthorne
中科院分区:
文献类型:
--
作者:
G. Harlow;F. Hawthorne
Abstract The crystal structures of herderite, CaBePO4[F0.75(OH)0.25], a = 9.7446(4), b = 7.6769(3), c = 4.7633(2) Å, β = 90.667(1)°, V = 356.31(4) Å3, P21/a, and Z = 4, from the Mogok Stone Tract, Myanmar, and hydroxyl-herderite, CaBePO4[(OH)0.52F0.48], a = 9.7615(4), b = 7.6680(3), c = 4.7853(2) Å, β = 90.184(1)°, V = 358.18(4) Å3, P21/a, and Z = 4, from the Sauberg mine, Morgenröther Zug, Ehrenfriedersdorf, Germany, have been refined to R1 indices of 1.7%, in both cases, using MoKα single-crystal X-ray diffraction data. Herderite from Mogok is associated with complex rare-element beryl-type granite pegmatite. Most herderite-series minerals are the product of late-stage processes in granite pegmatite evolution, typically of an exsolved fluid upon crystallization, and significant F-enrichment in these fluids appears to result in the domination of herderite over hydroxyl-herderite. Herderite is now documented from Mogok, Myanmar; Yichung, China; Brazil; and probably Erongo, Namibia. The pegmatites at Ehrenfriedersdorf, Germany have produced samples at the boundary between herderite and hydroxyl-herderite, if not possibly herderite as well.