【摘要】 <正> 1982年夏天,作者在河北省涉县符山铁矿区调查时,发现了一种形态罕见的绿帘石双晶晶体。其外形为沿C轴伸展的柱体,呈凸多面体形态,如图1所示。从外形看酷似一个单晶体,很难判断是双晶。更多还原

【Abstract】 A twinning crystal of epidote with a rare morphological features was discovered in Hebei province. It was investigated by X-ray single crystal photo methods. Laue and Weissenberg photographs show that the twinning has pseudo-orthorhombic mmm symmetry. The investigation proves that the type of twinning is a diagonal glide twin on (100) plane passing through the chains of A1 atoms and that, in macroscopic observation, the twinning appears as a fairly regular and simple contact twin on composition plane (100). Furthermore, according to the intensities of corresponding reflections, it reveals that the two individuals of the determined twin have nearly equal更多还原