中文摘要：

对α-石英双晶上具有不同结晶学意义的晶面和切面进行了腐蚀像的微分干涉显微镜（DIC）观察与研究。经研究发现，在鉴定道芬双晶与巴西双晶上，除了双晶缝合线有差异（道芬双晶双晶缝合线为曲线而巴西双晶的双晶缝合线为直线）外，不同的结晶学晶面或切面上这两种双晶的腐蚀像也各不相同。在六方柱{1010}面存在道芬双晶处，直角梯形蚀坑的方位关系为二次轴关系；六方柱{1010}面上存在巴西双晶处，直角梯形蚀坑的方位关系为对称面关系。菱面体{1011}面上存在道芬双晶处，道芬双晶双晶缝合线两端分别是菱面体正形、菱面体负形出露处，导致蚀坑形状不同；菱面体{1011}面上存在巴西双晶处，不规则三角形蚀坑形态的方位关系为对称面关系；三方柱切面{1120}面上存在道芬双晶处，道芬双晶双晶缝合线两端分别是三方柱正形、三方柱负形出露处，导致蚀坑形状不同；三方柱切面{11120}面上存在巴西双晶处，椭圆形或四边形蚀坑方位应为对称面关系，但实验中未见到。这一研究对认清α-石英道芬双晶和巴西双晶腐蚀像的对称关系，鉴定α-石英的双晶类型具有理论与实际意义。

英文摘要：

Based on the observation under a differential interference contrast microscopy （DIC）, the etching figure of faces and sections with different crystallographic significance on e-quartz twinning was studied. It was revealed that Brazil was straight. Further more, different the Dauphine partition line was curvy, while that of crystallographic faces and sections had different twinning etching figures. On the hexagonal prism face {1010}, Dauphine twinning showed two-fold symmetry between the trapezoidal etching pits of individuals, while Brazil twinning showed symmetry plane between the trapezoidal etching pits of individuals. On the rhombohedron face {1011} ,Dauphine twinning showed different shapes of etching pits between individuals, because rhombohedron positive form{ 1011} and negative form {0111} appeared on both sides of twin partition line, while Brazil twinning showed symmetry plane between the irregular triangle etching pits of individuals. On the trigonal prism section （1120）, Dauphine twinning showed different shapes of etching pits between individuals,because trigonal prism positive form{ 1120} and negative form {2110} appeared on both sides of twin partition line,while Brazil twinning should show symmetry plane between the ellipse or quadrilateral etching pits of individuals, which was not observed. This research was important to understand the symmetry property on Dauphine and Brazil twinning of α- quartz and provided a useful method for the identification of the two kinds of twinning.