サークル珠'成因解明の研究 : 真珠層構造面からのアプローチ

概要

論文の詳細を見る
A commercial term "Circle Pearl" has been used to denote pearls showing circumferential ditches or depressions, which are often encountered particularly among cultured black pearls. It is important to understand how such defects are formed so as to reduce percentage of "circle pearls" in culturing pearls. The present paper reports optical and scanning electron microscopic observations on the internal structures of nacreous layers revealed by bisecting "circle pearls" of various forms, and flat pearls formed on flat shape nucleus, twin pearls formed on two nuclei. The following factors were investigated:sectional color distribution, stage of initiation of circles, deviation of circles from symmetry, the degree of continuation of aragonite layers, thickness and number of aragonite layers at depressed and elevated portions, comparison of nacreous structure between twin and flat pearls, comparison among circle, twin and flat pearls. Based on these observations, two possible mechanisms on the origin of circle pearls have been proposed;one assumes wrinkles formed on pearl sac due to illness of mother pearls or external stress, and the other assumes rotation of nucleus in the pearl sac.
宝石学会(日本)の論文
1996-12-31