THE MESS THAT IS “ALLANITE”
THE MESS THAT IS “ALLANITE”
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“Allanite”的混乱
DOI：
10.2113/gscanmin.40.5.1411
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发表时间：
2002
影响因子：
0.9
通讯作者：
T. S. Ercit
中科院分区：
文献类型：
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作者：
T. S. Ercit
“褐帘石”是属于绿帘石群的一个定义不明确的物种集合。过去，“allanite”被定义为仅含镧，但最近，它被定义为在A2位点以镧为主。allanite亚群的种类包括allanite-(Ce)、allanite-(La)、allanite-(Y)、androite -(La)、dissakite -(Ce)、dollaseite-(Ce)和khristovite-(Ce)。由于缺乏对Nickel & Mandarino（1987）的建议的认可，以及对亚群中在其物种名称中有“allanite”的成员与没有“allanite”的成员之间的关系的认识，导致了在命名物种和使用“allanite”一词方面的许多错误。最近发表的十种方法描述了如何计算相关公式。结合对Si， Cr， V， mn2 +和a位空位行为的新观察，对每一种都进行了回顾。这一评价的结果是推荐的计算公式的程序，其中包括6个（M + T）阳离子和12个（O，F,Cl） + 1（OH）。对已公布的allanite亚群矿物组成公式的重新计算表明，一些明显的新物种更适合解释为常规端元之间的中间固溶体；然而，至少有五种潜在的新物种有待描述。
“Allanite” is a poorly defined collection of species belonging to the epidote group. In the past, “allanite” was defined as merely being lanthanon-bearing, but more recently, it is defined as being Ln-dominant at the A2 site. Species of the allanite subgroup include allanite-(Ce), allanite-(La), allanite-(Y), androsite-(La), dissakisite-(Ce), dollaseite-(Ce) and khristovite-(Ce). Lack of recognition of the recommendations of Nickel & Mandarino (1987), and of the relation between members of the subgroup with “allanite” in their species name and those without, has led to a number of errors in naming species and in use of the term “allanite”. Ten methods have recently been published describing how the relevant formulae may be calculated. Each is reviewed in conjunction with new observations on the behavior of Si, Cr, V, Mn 2+ and A-site vacancies. This evaluation results in a recommended procedure for the calculation of the formula involving a basis of 6 (M + T) cations and 12(O,F,Cl) + 1(OH). Recalculation of the formulae of published compositions of allanite-subgroup minerals shows that some apparently new species are better interpreted as intermediate solid-solutions between conventional end-members; there are, however, at least five potentially new species awaiting description.