Re-Examination of Berlinite (AlPOsub4/sub) from Cioclovina Cave, Romania

Bogdan P. Onac, Herta S. Effenberger

Research output: Contribution to journalArticlepeer-review

Abstract

Berlinite is a mineral indicative of high-temperature formation and, therefore, it would not be expected to be present in a sedimentary environment. In this study, we review the characteristics of a berlinite-bearing deposit and present a single-crystal structure investigation based on X-ray data: the refinement converged at R1(F) = 0.0276, wR2(F 2 ) = 0.0657 for 677 reflections (2θ MoKα ≤ 70°) and 31 variables in space-group P3 1 21 [a = 4.9458(10), c = 10.9526(20) Å, V = 232.0 Å 3 , Z = 3{AlPO 4 }]. The average bond distances within the two crystallographically unique TO 4 tetrahedra are 1.734 and 1.526 Å, respectively. From the scattering power at these T sites and the stereochemistry, the presence of an AlO 4 tetrahedron linked to a PO 4 tetrahedron is established. Consequently, the sample from Cioclovina Cave is verified as AlPO 4 (modification berlinite), reconfirming the first description of this mineral from a sedimentary occurrence, which underwent an obvious natural heating process.

Original languageAmerican English
JournalAmerican Mineralogist
Volume92
DOIs
StatePublished - Jan 1 2007

Keywords

  • Berlinite
  • Cioclovina Cave
  • Romania
  • cave minerals

Disciplines

  • Earth Sciences
  • Geology
  • Physical Sciences and Mathematics

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