人造宝石のX線的研究 (第1報)
1950 年 6 巻 1 号 p. 7-13
詳細
1950 年 6 巻 1 号 p. 7-13
The lattice constants of two artificially prepared jewels were determined using both the ordinary Debye-Scherrer and the back reflection methods and the following values were obtained :
α (kx) c (kx) temperature
white corundum 4.75320 12.95198 31°
ruby 4.75683 12.98843 31°
The latter contains several percent of chromic oxide.
The direction of crystal growth and the defects in crystals of a number of these jewels were investigated by the divergent-beam back reflection method. The specimens are of the form of an elongated drop and split into two parts by light hammering, the fracture surfaces being parallel to the longer axis of the drops (i. e, the direction of crystal growth) . The hexagonal axes of individual domains within a drop lie in the plane of fracture. The distribution of these axes within the plane, is somewhat scattered and in most cases it lies nearly perpendicular to the direction of the longer axes in the case of white corundum whereas it prefers the direction nearly parallel to the direction of growth in the case of ruby.
White corundum usually exhibits perfect structure but frequently consists of minute crystals, several millimeteres in diameter intersecting in few minutes, thus forms a mosaic structure. Ruby always shows imperfect structure, and its mosaic structure is usually built up by rows of crystals having. stringlet forms.
