The note describes (100) stacking faults in kyanite from a staurolite-kyanite intergrovrth with a displacement vector R : 7zb. Di-ffraction spots k * 2n are streaked and only with those reflections stacking faults are in contrast, which is interpreted as due to a displacement of thb on the,(100) faults. This produces groups of two corner-sharing tetrahedra. If stacking faults occur periodically...

The solubility of the assemblage corundum + kyanite in H2O was determined at 700 C and 10 kbar, using a piston-cylinder apparatus and rapid-quench/fluid-extraction techniques. Weighted mean concentrations of total Al and Si were 5.80 ± 0.03 mmol kg H2O and 0.308 ± 0.003 mol kg )1 H2O, respectively (1r errors). The Al concentration is nearly five times higher than that of corundum solubility in ...

Different models are discussed to interpret the presence of kyanite as a stable phase in contact aureoles especially in the andalusite-, sillimanitebearing aureoles. In such aureoles the polymorphic sequence kyanite → andalusite → sillimanite can be explained in terms of an essentially isobaric path during which kyanite initially crystallises from the breakdown of pyrophyllite or more likely mu...

Minerals, fluid inclusions and stable isotopes have been studied in ultrahigh-pressure (UHP) OH-rich topaz^kyanite quartzites from Hushan (west of Dongai), in southern Sulu (China). The quartzites underwent a metamorphic evolution characterized by a peak stage (3 5 GPa and 730^8208C) with the anhydrous assemblage coesiteþ kyanite I, followed by an early near-isothermal decompression stage (2 9 ...

We carried out reversed piston-cylinder experiments on the equilibrium paragonite = jadeite + kyanite + H2O at 700 C, 1.5–2.5 GPa, in the presence of H2O-NaCl fluids. Synthetic paragonite and jadeite and natural kyanite were used as starting materials. The experiments were performed on four different nominal starting compositions: X(H2O)=1.0, 0.90, 0.75 and 0.62. Reaction direction and extent w...

the relations of fibrolite-biotite are discussed by presenting data from the ardara aureole, nw ireland. biotite-fibrolite intergrowths are developed in all three aureole zones including: the outer kyanite-bearing andalusite zone, the middle kyanite-free andalusite zone and the inner prismatic sillimanite zone. a strain-assisted mechanism is proposed for the fibrolitisation of biotite in the ar...

The Lyagkomina occurrence of kyanite amphibolites (the Belomorian Province the Fennoscandian Shield) is confined to an amphibolite boudin among kyanite-garnet-biotite and garnet-biotite gneisses Chupa Sequence. main rock types at are meso- melanocratic garnet-kyanite with large (more than 1 cm in length) kyanite-garnet small kyanite. There also leucocratic garnet-biotite-amphibole-plagioclase r...

The process of mullitization of kyanite concentrate was studied at different conditions of heat treatment (1400– 1600 °C and 0.5 – 3.5 hours) and particle size of raw materials (38-300 ?m). Kyanite concentrate was obtained fromore-dressing of kyanite deposits of Mishidowan-Bafgh region at 100 km northeastern part of Yazd. The results ofmicrostructure (shape, distribution and size of the grains)...

The current configuration of the Alpujarride complex (Befic Orogen) comprises a stack of thinned tectonic units, made up mainly of continental crest. P T path modelling in different levels of an Alpujarride unit (the Salobrefia tectonic unit) reveals a high-pressure metamorphic stage followed by subsequent decompression at nearly isothermal conditions. Nevertheless, the P T conditions differ fr...