表生还原条件下翡翠水岩反应的热力学计算

Thermodynamic Calculation on Fluid-Rock Interaction of Jadeite Jade in Secondary Reducing Process

一些翡翠在表生还原条件下可观察到明显的水岩反应过程以及颜色与组织的改变。根据地质现象,从热力学计算的角度探讨了翡翠中的主矿物硬玉发生水岩反应后形成部分新的自生矿物的可能性。热力学计算的结果显示,在表生作用过程中,在环境存在额外的Mg2+与Fe2+的条件下,翡翠最易与Mg2+和Fe2+发生反应生成绿泥石。该结果为大多数无色翡翠经过表生还原作用后出现暗绿色-水绿色的颜色提供了一定的理论解释。

The fluid-rock interaction in some jadeite jade,as well as the enhancement of colour and structure could be observed in the secondary reducing process.Based on the geological phenomena,the possibility that some new authigenic minerals are formed by the jadeite in fluid-rock interaction is discussed according to the thermodynamic calculation.The results show that the jadeite jade is most likely to have a reaction with Mg2＋and Fe2＋ so as to form chlorite in the presence of additional Mg2＋and Fe2＋ and the secondary reducing process,which offer the theoretical explanation for the colour changes of the colourless jadeite jade in the secondary reducing process.