中文摘要：

本文采用NaOH-KOH混合熔融物和KOH溶液对石榴子石晶体各种不同的结晶学方向的晶面（切面）进行腐蚀实验,建立了石榴子石碱腐蚀像的立体模型,并与酸（HF溶液）腐蚀像模型进行对比。研究发现碱腐蚀像与酸腐蚀像一样能很好的反映晶体的对称特点,并发现在{100}、{110}晶面（切面）上碱腐蚀像与酸腐蚀像相同,而在{120}、{221}、{111}、{211}晶面（切面）上,碱腐蚀像与酸腐蚀像不同。该研究可以用来对石榴子石族矿物进行结晶学定向,同时具有揭示矿物所处地质环境酸碱性的指示意义。

英文摘要：

In this paper,NaOH-KOH mixture of melt and KOH solution were used to corrode a garnet crystal.The etch figures on faces（or sections） with different crystallographic directions were observed,and a stereographic model of etch figures were established.The difference between the etch figures formed by HF solution and alkaline reagents on the same crystal face or section was also analyzed.It is indicated that both alkaline etching and acid etching can reflect the characteristics of the crystal symmetry.Comparison shows that alkaline etching figure is the same as acid etching figure on {100} and {110},but alkaline etching figure is different from acid etching figure on {120}、{221}、{111} and {211}.The study can be used for the crystallography orientation of garnet group minerals,and it is also be used to reveal the pH geological environment for garnet formation.