An unusual highly hydrated and Na-depleted variety of elpidite was identified in a hydrothermally altered peralkaline pegmatite at Mt. Yukspor in the Khibiny alkaline complex, Kola Peninsula, Russia. It differs from ‘ordinary’ elpidite, ideally Na2ZrSi6O15⋅3H2O, in its crystal chemical features, infrared spectrum and optical characteristics. The chemical composition (wt.%, electron microprobe, H2O by TGA) is: Na2O 5.45, K2O 0.67, CaO 0.05, SiO2 60.32, TiO2 1.34, ZrO2 18.43, Nb2O5 0.65, H2O 12.80, total 99.71. The empirical formula calculated on the basis of 6 Si and 15 O atoms is [(Na1.05K0.08Ca0.01)Σ1.14(H3O)0.74]Σ1.88(Zr0.89Ti0.10Nb0.03)Σ1.02Si6O15⋅3.47H2O; the H2O:H3O ratio was calculated from the charge balance requirement, taking into account the results of crystal structure refinement. The highly hydrated variety of elpidite is orthorhombic, Pma2, a = 14.5916(6), b = 7.3294(3), c = 7.1387(2) Å, V = 763.47(5) Å3 and Z = 2. The crystal structure was solved from single-crystal X-ray diffraction data, R1 = 3.43%. The structure is based upon an elpidite-type heteropolyhedral Zr–Si–O framework with Na+ and H3O+ cations and H2O molecules in the zeolitic channels. Hydronium cations substitute for water molecules in one of the extra-framework sites. This variety of elpidite could be considered as an intermediate product of natural ion-exchange reaction between ‘ordinary’ elpidite and a low-temperature hydrothermal fluid.

在俄罗斯科拉半岛 Khibiny 碱性复合体的 Yukspor 山的热液蚀变过碱性伟晶岩中发现了一种不寻常的高度水化和贫钠的锂辉石。它在晶体化学特征、红外光谱和光学特性方面不同于“普通”云母，理想情况下是 Na 2 ZrSi 6 O 15 ⋅3H 2 O。化学成分（wt.%，电子探针，TGA测得的H 2 O）为：Na 2 O 5.45、K 2 O 0.67、CaO 0.05、SiO 2 60.32、TiO 2 1.34、ZrO 2 18.43、Nb 2 O 5 0.65、 H 2O 12.80，总分 99.71。基于6个Si和15个O原子计算的经验公式为[(Na 1.05 K 0.08 Ca 0.01 ) Σ1.14 (H 3 O) 0.74 ] Σ1.88 (Zr 0.89 Ti 0.10 Nb 0.03 ) Σ1.02 Si 6 O 15 ⋅3.47H 2 O；H 2 O:H 3 O 比率是根据电荷平衡要求计算的，同时考虑了晶体结构细化的结果。的高度水合的各种elpidite的为斜方晶，PMA 2，一个= 14.5916(6), b = 7.3294(3), c = 7.1387(2) Å, V = 763.47(5) Å 3和Z = 2. 晶体结构由单晶 X 射线衍射数据R 1 = 3.43%。该结构基于沸石通道中具有 Na +和 H 3 O +阳离子以及 H 2 O 分子的锂辉石型杂多面体 Zr-Si-O 骨架。水合氢阳离子替代框架外位点之一中的水分子。这种锂云母可以被认为是“普通”锂云母与低温热液流体之间自然离子交换反应的中间产物。