Samarskite-(Y), the mineral known for almost 180 years only in metamict (X-ray amorphous) state, was found as non-metamict crystals in sanidinites of the Laach Lake (Laacher See), Eifel volcanic region, Germany. The crystal structure has been solved for the first time and refined to R1 = 1.1% based on 838 observed [I > 2σ(I)] independent reflections. Samarskite-(Y) is monoclinic, P2/c, a 9.8020(8), b 5.6248(3), c 5.2073(4) Å, β 93.406(4)°, V 286.59(4) Å3, Z = 2. The empirical formula (calculated on 8 O apfu) is $$\left[ {\left( {{\text{Y}}_{0. 2 5} Ln_{0. 1 8} } \right)_{\varSigma 0. 4 3} {\text{Th}}_{0. 3 7} {\text{U}}_{0. 1 3}^{ 4+ } {\text{Ca}}_{0.0 3} } \right]_{\varSigma 0. 9 6} \left( {{\text{Fe}}_{0. 7 3}^{ 3+ } {\text{Mn}}_{0. 1 8}^{ 2+ } } \right)_{\varSigma 0. 9 1} \left( {{\text{Nb}}_{ 1. 8 5} {\text{Ti}}_{0.0 6} {\text{Zr}}_{0.0 6} {\text{Ta}}_{0.0 3} {\text{W}}_{0.0 2} } \right)_{\varSigma 2.0 2} {\text{O}}_{ 8}$$Y0.25Ln0.18Σ0.43Th0.37U0.134+Ca0.03Σ0.96Fe0.733+Mn0.182+Σ0.91Nb1.85Ti0.06Zr0.06Ta0.03W0.02Σ2.02O8. Samarskite-(Y) from the type locality, the Blyumovskaya Pit, Ilmeny Mountains, South Urals, Russia, was studied for comparison; electron microprobe data showed the same species-defining constituents and stoichiometry: $$\left[ {\left( {{\text{Y}}_{0. 3 4} Ln_{0. 20} } \right)_{\varSigma 0. 5 4} {\text{U}}_{0. 4 2}^{ 4+ } {\text{Th}}_{0.0 3} } \right]_{\varSigma 0. 9 9} \left( {{\text{Fe}}_{0. 8 6}^{ 3+ } {\text{Mn}}_{0.0 8}^{ 2+ } } \right)_{\varSigma 0. 9 4} \left( {{\text{Nb}}_{ 1. 1 4} {\text{Ta}}_{0. 70} {\text{Ti}}_{0. 1 5} } \right)_{\varSigma 1. 9 9} {\text{O}}_{ 8}$$Y0.34Ln0.20Σ0.54U0.424+Th0.03Σ0.99Fe0.863+Mn0.082+Σ0.94Nb1.14Ta0.70Ti0.15Σ1.99O8. Samarskite-(Y) is the first example of cation-ordered niobate structurally related to layered double tungstates AMW2O8, the compounds used as luminophors and active media in solid-state lasers. The pseudo-layered framework of the mineral can be derived from that of wolframite via substitution of W for Nb, whereas each second [FeO6] layer is replaced by [YO8] one. The resulting sequence of layers can be expressed as -[AO8]-[BO6]-[MO6]-[BO6]- leading to the formula AMB2O8 in which A = Y, Ln, Th, U4+, Ca; M = Fe3+, Mn2+; and B = Nb, Ta, Ti. The end-member formula of samarskte-(Y) is YFe3+Nb2O8 (approved by the Commission on New Minerals, Nomenclature and Classification, International Mineralogical Association, memorandum 90-FH/18).

中文翻译：

---

samarskite-(Y), YFe3+Nb2O8 的重新定义和晶体化学：与层状双钨酸盐结构相关的阳离子有序铌酸盐

Samarskite-(Y) 是一种已知近 180 年的矿物，仅以变质晶（X 射线无定形）状态存在，在德国埃菲尔火山区拉赫湖 (Laacher See) 的花青石中以非变质晶晶体的形式被发现。基于 838 次观察到的 [I > 2σ(I)] 独立反射，首次解决了晶体结构，并将其细化为 R1 = 1.1%。Samarskite-(Y) 是单斜晶系，P2/c, a 9.8020(8), b 5.6248(3), c 5.2073(4) Å, β 93.406(4)°, V 286.59(4) Å3, Z = 2。经验公式（在 8 O apfu 上计算）为 $$\left[ {\left( {{\text{Y}}_{0. 2 5} Ln_{0. 1 8} } \right)_{\varSigma 0 . 4 3} {\text{Th}}_{0. 3 7} {\text{U}}_{0. 1 3}^{ 4+ } {\text{Ca}}_{0.0 3} } \right]_{\varSigma 0. 9 6} \left( {{\text{Fe}}_{0. 7 3 }^{ 3+ } {\text{Mn}}_{0. 1 8}^{ 2+ } } \right)_{\varSigma 0. 9 1} \left( {{\text{Nb}}_ { 1. 8 5} {\text{Ti}}_{0.0 6} {\text{Zr}}_{0. 0 6} {\text{Ta}}_{0.0 3} {\text{W}}_{0.0 2} } \right)_{\varSigma 2.0 2} {\text{O}}_{ 8}$ $Y0.25Ln0.18Σ0.43Th0.37U0.134+Ca0.03Σ0.96Fe0.733+Mn0.182+Σ0.91Nb1.85Ti0.06Zr0.06Ta0.03W0.02Σ2.02O8。Samarskite-(Y) 来自俄罗斯南乌拉尔伊尔梅尼山脉的 Blyumovskaya 坑，用于比较；电子微探针数据显示相同的物种定义成分和化学计量：$$\left[ {\left( {{\text{Y}}_{0. 3 4} Ln_{0. 20} } \right)_{\ varSigma 0. 5 4} {\text{U}}_{0. 4 2}^{ 4+ } {\text{Th}}_{0.0 3} } \right]_{\varSigma 0. 9 9} \left( {{\text{Fe}}_{0. 8 6 }^{ 3+ } {\text{Mn}}_{0.0 8}^{ 2+ } } \right)_{\varSigma 0. 9 4} \left( {{\text{Nb}}_{ 1 . 1 4} {\text{Ta}}_{0. 70} {\text{Ti}}_{0. 1 5} } \right)_{\varSigma 1. 9 9} {\text{O} }_{ 8}$$Y0.34Ln0.20Σ0.54U0.424+Th0.03Σ0.99Fe0.863+Mn0.082+Σ0.94Nb1.14Ta0.70Ti0.15Σ1.99O8。Samarskite-(Y) 是第一个在结构上与层状双钨酸盐 AMW2O8 相关的阳离子有序铌酸盐的例子，该化合物在固态激光器中用作发光体和活性介质。矿物的伪层状框架可以通过用 W 代替 Nb 从黑钨矿中获得，而每第二个 [FeO6] 层都被 [YO8] 层代替。由此产生的层序列可以表示为 -[AO8]-[BO6]-[MO6]-[BO6]- 导致公式 AMB2O8，其中 A = Y、Ln、Th、U4+、Ca；M = Fe3+、Mn2+；B = Nb、Ta、Ti。samarskte-(Y) 的端元分子式为 YFe3+Nb2O8（由国际矿物学协会新矿物命名和分类委员会批准，备忘录 90-FH/18）。在固态激光器中用作发光体和活性介质的化合物。矿物的伪层状框架可以通过用 W 代替 Nb 从黑钨矿中获得，而每第二个 [FeO6] 层都被 [YO8] 层代替。由此产生的层序列可以表示为 -[AO8]-[BO6]-[MO6]-[BO6]- 导致公式 AMB2O8，其中 A = Y、Ln、Th、U4+、Ca；M = Fe3+、Mn2+；B = Nb、Ta、Ti。samarskte-(Y) 的端元分子式为 YFe3+Nb2O8（由国际矿物学协会新矿物命名和分类委员会批准，备忘录 90-FH/18）。在固态激光器中用作发光体和活性介质的化合物。矿物的伪层状框架可以通过用 W 代替 Nb 从黑钨矿中获得，而每第二个 [FeO6] 层都被 [YO8] 层代替。由此产生的层序列可以表示为 -[AO8]-[BO6]-[MO6]-[BO6]- 导致公式 AMB2O8，其中 A = Y、Ln、Th、U4+、Ca；M = Fe3+、Mn2+；B = Nb、Ta、Ti。samarskte-(Y) 的端元分子式为 YFe3+Nb2O8（由国际矿物学协会新矿物命名和分类委员会批准，备忘录 90-FH/18）。由此产生的层序列可以表示为 -[AO8]-[BO6]-[MO6]-[BO6]- 导致公式 AMB2O8，其中 A = Y、Ln、Th、U4+、Ca；M = Fe3+、Mn2+；B = Nb、Ta、Ti。samarskte-(Y) 的端元分子式为 YFe3+Nb2O8（由国际矿物学协会新矿物命名和分类委员会批准，备忘录 90-FH/18）。由此产生的层序列可以表示为 -[AO8]-[BO6]-[MO6]-[BO6]- 导致公式 AMB2O8，其中 A = Y、Ln、Th、U4+、Ca；M = Fe3+、Mn2+；B = Nb、Ta、Ti。samarskte-(Y) 的端元分子式为 YFe3+Nb2O8（由国际矿物学协会新矿物命名和分类委员会批准，备忘录 90-FH/18）。