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 language | American English |
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Journal | American Mineralogist |
Volume | 92 |
DOIs | |
State | Published - Jan 1 2007 |
Keywords
- Berlinite
- Cioclovina Cave
- Romania
- cave minerals
Disciplines
- Earth Sciences
- Geology
- Physical Sciences and Mathematics