Orientation of the boundaries of out-of-step domains in anorthite
Open Access
- 1 June 1968
- journal article
- Published by Mineralogical Society in Mineralogical Magazine and Journal of the Mineralogical Society
- Vol. 36 (282) , 814-819
- https://doi.org/10.1180/minmag.1968.036.282.08
Abstract
The orientation of the boundaries of out-of-step domains in ‘transitional’ anorthite has been deduced from the direction of elongation of the diffuse X-ray reflections h + h + l = 2n + 1 in selected precession photographs. The reflections are elongated normal to which is in the zone and contains the body-centring vector (a+b−c)/2. The structure is presumed to be perfect parallel to . Atoms in essentially identical, primitive anorthite-like domains are related across the out-of-step domain boundaries by body-centring vectors. Increasing diffuseness of the h + k + l = 2n + 1 reflections indicates progressively smaller domains (more frequent domain boundaries), and when thesereflections disappear, the structure has become body-centred on the average.Keywords
This publication has 8 references indexed in Scilit:
- The structure of bytownite (`body-centred anorthite')Acta Crystallographica, 1966
- Order and disorder - II. Theory of diffraction effects in the intermediate plagioclase felsparsProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1960
- Precession photographs of reciprocal-lattice rods in HfFe2Zeitschrift für Kristallographie, 1959
- An optical method of studying the diffraction from imperfect crystals III. Layer structures with stacking faultsProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1958
- The structures of the plagioclase felspars. V. The heat-treatment of lime-rich plagioclasesMineralogical Magazine and Journal of the Mineralogical Society, 1954
- Long-range-short-range order in calcic plagioclases as a continuous and reversible function of temperatureActa Crystallographica, 1954
- Discussion on the anorthite superstructureActa Crystallographica, 1954
- Unusual X-ray diffraction effects from a crystal of wollastoniteActa Crystallographica, 1953