Abstract

The crystal structure of a potentially new mineral, the Fe²⁺-dominant analogue of armalcolite with the idealized formula Fe²⁺Ti₂O₅ has been solved. The sample studied originates from a pneumatolytic association related to the lamproite complex of SE Spain. The mineral is orthorhombic, space group Cmcm, the unit-cell parameters are a = 3.7325(1) Å, b = 9.7649(4) Å, c = 9.9902(3) Å, V = 364.12(2) ų. The crystal-chemical formula \({{^{M}}^{1}}{{({\text{M}}{{{\text{g}}}_{{0.19}}}{\text{Fe}}_{{0.25}}^{{2 + }}{\text{Fe}}_{{0.26}}^{{3 + }}{\text{T}}{{{\text{i}}}_{{0.30}}})}^{{2.86 + }}}\)\({{{{[}^{M}}^{2}{{({\text{T}}{{{\text{i}}}_{{0.65}}}{\text{Fe}}_{{0.27}}^{{3 + }}{\text{Fe}}_{{0.08}}^{{2 + }})}^{{3.57 + }}}]}_{2}}{{{\text{O}}}_{5}}\) (Z = 4) is in good agreement with the chemical composition of the mineral.

中文翻译：

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假板钛矿组：铝辉石Fe 2+类似物的晶体化学特征

摘要

解决了一种潜在的新矿物的晶体结构，即具有理想化分子式Fe ²⁺ Ti ₂ O ₅的粉煤灰石的Fe ²⁺占主导地位的类似物。研究的样品源自与西班牙东南部的褐铁矿复合物有关的肺气溶解作用。矿物是斜方晶系，空间群CMCM，晶胞参数为一个= 3.7325（1）埃，b = 9.7649（4），C ^ = 9.9902（3）埃，V = 364.12（2）埃³。晶体化学式\（{{^^ M}} ^ {1}} {{（{\ text {M}} {{{\ text {g}}} _ {{0.19}}} {\ text {Fe}} __ { {0.25}} ^ {{{2 +}} {\ text {Fe}} _ {{0.26}} ^ {{3 +}} {\ text {T}} {{{\ text {i}}} __ { {0.30}}}）} ^ {{2.86 +}}} \\）\（{{{{{} ^ {M}} ^ {2} {{（{\ text {T}} {{{\ text { i}}} _ {{0.65}}} {\ text {Fe}} _ {{0.27}} ^ {{3 +}} {\ text {Fe}} _ {{0.08}} ^ {{2 +} }）} ^ {{{3.57 +}}}}} _ {2}} {{{\ text {O}}} _ {5}} \）（Z = 4）与矿物。