Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 1 October 1976:
Vol. 194. no. 4260, pp. 105 - 107
DOI: 10.1126/science.194.4260.105
Prev | Table of Contents | Next

Articles

Sanidine: Predicted and Observed Monoclinic-to-Triclinic Reversible Transformations at High Pressure

ROBERT M. HAZEN 1

1 Department of Mineralogy and Petrology, University of Cambridge, Cambridge CB2 3EW, England

High sanidine, (K,Na)AlSi3O8, transforms reversibly to a triclinic phase at high pressure. This is analogous to the high-temperature monalbite transformation. Disordered alkali feldspars of various compositions have unit-cell dimensions which are very similar at the transition (a = 8.30 Å, b = 12.97 Å, c = 7.14 Å, and beta = 116.2°), indicating that the transformation is structurally controlled. Changes in temperature, pressure, and the sodium/potassium ratio cause similar structural variations: angles between adjacent, rigid tetrahedra vary to accommodate changing effective alkali cation sizes.

Submitted on June 16, 1976
Revised on July 23, 1976


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
COMPRESSIBILITY AND HIGH-PRESSURE BEHAVIOR OF Ab63Or27An10 ANORTHOCLASE.
F. Nestola, N. Curetti, P. benna, G. Ivaldi, R. J. Angel, and E. Bruno (2008)
Can Mineral 46, 1443-1454
   Abstract »    Full Text »    PDF »
A simple predictive model for the thermal expansion of AlSi3 feldspars.
G. L. Hovis, J. R. Morabito, A. Spooner, A. Mott, E. L. Person, C. M. B. Henderson, J. Roux, and D. Harlov (2008)
American Mineralogist 93, 1568-1573
   Abstract »    Full Text »    PDF »
The high-pressure structural configurations of Ca0.2Sr0.8Al2Si2O8 feldspar: The IFormula-I2/c and I2/c-P21/c phase transitions.
P. Benna, F. Nestola, T. B. Ballaran, T. Balic-Zunic, L. F. Lundegaard, and E. Bruno (2007)
American Mineralogist 92, 1190-1199
   Abstract »    Full Text »    PDF »
High-pressure phase transitions in Ca0.2Sr0.8Al2Si2O8 feldspar.
F. Nestola, F. Nestola, T. B. Ballaran, P. Benna, M. Tribaudino, and E. Bruno (2004)
American Mineralogist 89, 1474-1479
   Abstract »    Full Text »    PDF »
High-pressure behaviour of lawsonite: a phase transition at 8.6 GPa.
I. DANIEL, G. FIQUET, P. GILLET, M. W. SCHMIDT, and M. HANFLAND (2000)
European Journal of Mineralogy 12, 721-733
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)