Contribution
The α-quartz trigonal symmetry revealed by fracture tests
Reuschlé, Thierry; Darot, Michel
European Journal of Mineralogy Volume 8 Number 4 (1996), p. 695 - 702
26 références bibliographiques
publié: Jul 29, 1996
manuscrit accepté: Mar 28, 1996
manuscrit reçu: Sep 6, 1995
DOI: 10.1127/ejm/8/4/0695
Abstract
Abstract Subcritical crack growth experiments on quartz single crystals have been carried out. Reproducibility of the results was checked by running tests on several samples in the same crack propagation direction. The results show the prominent role that water plays in controlling the crack velocity. Crack propagation tests run in two opposite directions show striking differences which confirm previous results. These differences are mainly due to the anisotropy of the quartz surface energy. Microstructural observations of the fracture surfaces for two opposite crack propagation directions give evidence for this anisotropy which is the consequence of the α-quartz trigonal symmetry. Our results confirm the subtle difference in the adjacent m directions, as already shown by electron channelling patterns.
Mots-clefs
α-quartz • fracture propagation • Double Torsion • fractography • surface energy.