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Pentaborate Polyanion in the Crystal Structure of Ulexite, NaCaB 5 O 6 (OH) 6 ⋅5H 2 O

1964; American Association for the Advancement of Science; Volume: 145; Issue: 3638 Linguagem: Inglês

10.1126/science.145.3638.1295

1095-9203

Joan R. Clark, Daniel E. Appleman,

X-ray Diffraction in Crystallography

Triclinic ulexite crystals contain isolated borate polyanions [B(5)O(6)(OH)(6)](3-) related to the well known pentaborate polyanion [B(5)O(6)(OH)(4)](-) by addition of two hydroxyl groups to two opposite B-O triangles. The isolated ulexite polyanions form the [B(5)O(7)(OH)(4)](n)(3n-) chains previously found in crystals of the related mineral probertite, NaCaB(5)O(7)(OH)(4).3H(2)O.