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Eudialyte [abbr. Eud ]

Year of discovery: 1801 (Kangerluarsuk Fjord, Greenland), 1952 (Japan)

Locality list: 0 locality of eudialyte

• Na₁₅Ca₆Fe₃Zr₃Si₂₆O₇₂(O,OH,H₂O)₄Cl₂
• Na₁₅(Ca,Ce)₆(Fe,Mn)₃Zr₃Si₂₆O₇₂(O,OH,H₂O)₄(Cl,OH)₂
• [Na⁺₁₅][Ca²⁺₆][Fe²⁺₃][Si⁴⁺][Si⁴⁺][Zr⁴⁺₃][Cl₂|(O,OH,H₂O)₄|(Si₃O₉)₂|(Si₉O₂₇)₂]^53-

• Class: Eudialyte group
• Class: Cyclosilicate (Single ring) - Oxide - Chloride
• Soluble in: HCl (Gel residue)
• Radioactive: Moderate

• Si => Nb: Ferrokentbrooksite

• Color: Red
• Streak: Pale pink
• Luster: Vitreous
• Diaphaneity: Translucent

• Cleavage: Distinct on {0001} (1 plane), Imperfect on {1010}, {1014}, and {11-20} (9 planes)
• Hardness: 5-6
• Density: 2.9

• System: Trigonal
• Group: (-3)m, R(-3)m
• Lattice: a=14.3, c=30.2