gems, jade, pyroxene jade, fei cui, jadeite, omphacite, kosmochlor, Guatemala

A small number of rough and polished specimens of a new dark blue omphacite “jade” were displayed by Ventana Mining Co. at the Pueblo Inn and by Leher Designs at the GJX show and at the Westward Look Resort. Ideally (Ca,Na)(Mg,Al)Si₂O₆, omphacite is a member of the pyroxene group, and is composed of a solid solution of jadeite and calcic clinopyroxene (e.g., diopside) with subordinate aegirine. The material was first recovered by one of these contributors (WRR) in June 2003, and so far it has been found in a relatively restricted part of a claim held by Ventana Mining Co.. The deposit is located in the Quebrada Seca area, near Carrizal Grande, Guatemala. (For information on recent jadeite discoveries in this area, see the Winter 2002 Gem News International, pp. 352–353.) The blue omphacite occurs as fine veins that cross-cut large alluvial boulders of greenish blue jadeite that were situated near outcrops consisting of blueschist, eclogite and jadeite. Because the veins are rather narrow (i.e., from 2 to 20 mm thick), the material lends itself to small cabochons and carvings.