Titre du document / Document title

POLYMORPH-METASOMATIC TEXTURES AT REPLACEMENT OF NICKELHEXAHYDRITE BY RETGERSITE

Auteur(s) / Author(s)

KULKOV A. M. ; GLIKIN A. E. ;

Résumé / Abstract

Polymorph transition running through metasomatic replacement was observed experimentally on the example of retgersite paramorph formation after nickelhexahydrite crystals. The process runs through a solution film placed on the initial crystal surface, which penetrates then into the intracrystal space at the replacement front. One or several secondary individuals grow into a comparatively perfect crystal up to the complete replacement; the individuals arc in a spontaneous orientation to the crystal. A fine-grain mass replaces defective crystals. A combined aggregate of individuals inserted into a finegrain mass is an intermediate case. Monocrystal pseudomorphs were synthesized for the first time in the case of non-isomorphic interaction. Conditions of the nickelhexahydritc metastable equilibrium and the retgersite stable equilibrium are closely related. They determine textural features at replacement reactions for this substance couple. Supersaturation of retgersite is relatively low in the vicinity of the eutonic point resulting in nucleation and development of single secondary crystals. A removing from the cutonic point causes an increase of supersaturation and mass precipitation of the secondary phase.

Revue / Journal Title

Zapiski Vserossijskogo mineralogičeskogo obŝestva   ISSN 0869-6055 

Source / Source

2007, vol. 136, n^o2, pp. 104-111 [8 page(s) (article)]

Langue / Language

Russe

Editeur / Publisher

Nauka, Sankt-Peterburg, RUSSIE, FEDERATION DE  (1992) (Revue)

Localisation / Location

INIST-CNRS, Cote INIST : 4673, 35400019807156.0110