Re-examination of berlinite (AlPO4) from the Cioclovina Cave, Romania

Autor(en)

Herta Silvia Effenberger

Abstrakt

Berlinite is a mineral indicative of high-temp. 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(F2) = 0.0657 for 677 reflections (2.theta.MoK.alpha. 70) and 31 variables in space-group P3121 [a = 4.9458(10), c = 10.9526(20) .ANG., V = 232.0 .ANG.3, Z = 3 {AlPO4}]. The av. bond distances within the two crystallog. unique TO4 tetrahedra are 1.734 and 1.526 .ANG., resp. From the scattering power at these T sites and the stereochem., the presence of an AlO4 tetrahedron linked to a PO4 tetrahedron is established. Consequently, the sample from Cioclovina Cave is verified as AlPO4 (modification berlinite), reconfirming the first description of this mineral from a sedimentary occurrence, which underwent an obvious natural heating process.

Organisation(en)

Institut für Mineralogie und Kristallographie

Journal

American Mineralogist: an international journal of earth and planetary materials

Band

92

Seiten

1998-2001

Anzahl der Seiten

4

ISSN

0003-004X

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

105113 Kristallographie, 105116 Mineralogie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/59407e5c-1213-4d72-8f10-2d409e43f49d