危地马拉紫色翡翠的矿物组成特征及意义

通过薄片鉴定、阴极发光、LIBS、LA-ICP-MS等手段,确定了危地马拉紫色翡翠的矿物组成有硬玉、钠长石、钙铝榴石、榍石与金红石,这些矿物的结晶顺序为金红石+榍石-白色硬玉-蓝紫色硬玉+钙铝榴石-钠长石,具有从温度降低的流体中结晶演化的特征。蓝紫色硬玉的Ti含量较高。在外观上,危地马拉紫色翡翠含有钙铝榴石造成的淡红色团块、含Ti硬玉造成的蓝紫色团块以及伴随这些团块的无色透明的钠长石,与缅甸产的紫色翡翠有较为明显的区别。

Mineral composition of the purple jadeite from Guatemala and its significance

The Guatemala purple jadeite jade (jadeitite) was studied by such means as thin section, cathode luminescence, LIBS and LA-ICP-MS. The results show that the common assemblage includes jadeite, albite, grossular, titanite and rutile, and the sequence of their crystallization is in order of titanite-white jadeite-bluish purple jadeite+grossular-albite, suggesting the evolution of fluids at decreasing temperature. The blue purple jadeite has higher Ti content. In appearance, the Guatemala purple jadeite shows that the pink purple mass is caused by grossular and the blue purple mass is caused by jadeite with higher Ti content and colorless transparent albite in association with these masses. These characteristics can distinguish Guatemala purple jadeite jade form Myanmar purple jadeite jade.