Les auteurs présentent une méthode d'étude statistique nouvelle des populations de zircon accessoire des roches endogènes ; cette méthode est basée sur la typologie des cristaux automorphes et subautomorphes. Les auteurs considèrent 194 types et sous˗types, observés ou théoriques, en fonction de la combinaison et du développement relatif des faces prismatiques et pyramidales. Une grille permet une représentation simple et précise des résultats.
Synthèses hydrothermales de zirconosilicates de sodium entre 300° C et 700° C, à une pression constante de 700 bars : catapléite, elpidite, vlasovite, keldyshite, Na₂ZrSiO₅, Na₁₄Zr₂Si₁₀O₃₁ ; et de deux nouvelles phases.
Études morphologiques et radiocristallographiques. Corrélations pétrogénétiques.
Authors discribing zircon crystals or studying lattice and structure of this mineral often use two different indexation modes for its faces. To avoid this confusion, we have set up reference indexations of all known faces of natural zircon crystals according ro radiocrystallographic datas.
All real dehedral angles formed by these faces are also determined and stereographic projection drawn up. Moreover, real angles formed by the main zircon edges and (001) are calculated.
From this we have drawn up original charts that could be of great help for the indexation of rocks accessory zircon crystals in slides.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.