JADEITITE FROM SYNM-KEU ULTRAMAFIC COMPLEX, POLAR URALS, RUSSIA

Abstract

Jadeitite is hosted as vein (up to 5m wide) by antigorite-dominated serpentinite bodies from Synm-Keu ultramafic complex, Polar Urals, Russia. Jadeitite is composed of Jadeite and Omphacite. It had experienced multi-stage jadeitizations indicated by color and structure of Jadeite. The Jadeite with gray-white color and coarse grain and massif structure, which has 54mol% - 88mol% Jadeite, is considered to be the stage-I Jadeite. The stage-II Jadeite that has light green color and fine crystal occurring as fine vein nodular in the white Jadeite contains 74mol% - 86mol% Jadeite. The last-stage Jadeite is green-emerald green color, medium-fine and nubble formed, which is translucency-lucency. Part of stage-II and stage-III jadeitite can be used as fine jewelry. Based on the occurrences of Jadeitite, crystal with growth zoning and fluid inclusions in jadeite, We consider that the jadeitite vein produced from Na-Al-Si-rich fluids at HP/LT conditions during active subduction/collisions.