Microporous slicates with the pharmacosiderite structure and the general formula A3–xH1+x[Ti4O4(SiO4)3](H2O)n (A = Na, K, Cu), (n = 6–9, x = 0–2) are outstanding in their ion-exchange properties. The ivanyukite mineral group consists of three species, one of which has two polymorphs. The minerals forming a progressive series: ivanyukite-Na-T → ivanyukite-Na-C → ivanyukite-K → Cu-rich ivanyukite-K → ivanyukite-Cu, have been studied by single-crystal X-ray diffraction, electron microprobe analysis and Raman spectroscopy. The microporous heteropolyhedral framework of the ivanyukite-group minerals is based on cubane-like [Ti4O4]8+ clusters that share common corners with SiO4 tetrahedra to form wide three-dimensional channels suitable for the migration of Na+, K+ and Cu2+ ions. Ivanyukite-Na-T that has a R3m symmetry loses Na+ in aqueous solutions via the substitution Na+ + O2‒ ↔ □ + OH‒, which allows for the migration of K+ ions and transformation of initial structure into the cubic (P$\bar{4}3m$) ivanyukite-Na-C polymorph or into ivanyukite-K, when most of Na is lost. Natural ivanyukite-Na-C is shown to contain domains of both R3m (subordinate) and P$\bar{4}3m$ (dominant) symmetry with the chemical composition determining the stability and dominance of cubic or trigonal forms. Incorporation of Cu into the crystal structure ivanyukite-K via the substitution K+ + OH− ↔ Cu2+ + O2− in aqueous solutions results in the formation of ivanyukite-Cu. Post-crystallisation processes (such as exchange of Na+, K+, Cu2+, and/or hydration/dehydration of primary phases) are widespread in hyperagpaitic rocks of the Kola alkaline massif and the respective mineral transformations contribute to the diversity of mineral species.

具有药铁矿结构和通式A 3– x H 1+ x [Ti 4 O 4 (SiO 4 ) 3 ](H 2 O) n ( A = Na, K, Cu), ( n = 6– 9, x = 0–2) 在离子交换性能方面表现突出。ivanyukite 矿物组由三个物种组成，其中一个具有两个多晶型。形成递进系列的矿物：ivanyukite-Na- T → ivanyukite-Na- C→ ivanyukite-K → 富铜 ivanyukite-K → ivanyukite-Cu，已通过单晶 X 射线衍射、电子探针分析和拉曼光谱进行了研究。ivanyukite族矿物的微孔杂多面体骨架基于类立方[Ti 4 O 4 ] 8+簇，与SiO 4四面体共享共角，形成适合Na +、K +迁移的宽三维通道和Cu 2+离子。Ivanyukite-NA- Ť具有- [R 3米对称性失去的Na +的水溶液中通过置换的Na ++ O 2‒ ↔ □ + OH ‒，它允许 K +离子迁移并将初始结构转化为立方 ( P $\bar{4}3m$ ) ivanyukite-Na- C多晶型物或转化为 ivanyukite-K，当大部分 Na 丢失时。天然 ivanyukite-Na- C显示包含R 3 m（次要）和P $\bar{4}3m$（主要）对称域，其化学成分决定了立方或三角形式的稳定性和优势。通过取代 K + + OH - ↔ Cu 2+将 Cu 并入晶体结构 ivanyukite-K+ O 2-在水溶液中导致形成ivanyukite-Cu。后结晶过程（例如 Na +、K +、Cu 2+ 的交换和/或初级相的水合/脱水）在 Kola 碱性地块的超胶石岩中广泛存在，并且各自的矿物转变有助于矿物的多样性物种。