珍珠和贝壳的晶体结构新结论

国内外贝类学界都认为贝壳角质层仅由贝壳素构成.棱柱层由方解石构成.珍珠层通常为霰石构成.日本的小林新二郎提出棱柱珍珠是方解石结构,国内外许多论文对此都没有提出异议.本研究采用X-射线对贝壳和棱柱珍珠衍射结果证明:(1)贝壳珍珠层全是是霰石结构,只有牡蛎(Ostrea rivularis)壳例外,符合以上理论;(2)棱柱层几乎全是霰石结构,只有牡蛎壳和紫色裂江珧(Pinna atropurpurea)壳的棱柱层是方解石结构,基本否定了以上理论;(3)角质层由有机物—贝壳素和方解石或霰石组成的,有些还含二氧化硅等杂质,这不完全相符上面理论;(4)棱柱珍珠完全是霰石结构,证明小林新二郎的结论是错误的.

New conclusions on the crystal structure of pearl and shell

Shellfish academics home and abroad believe that periostracum layer composed of only conchiolin. The prismatic layer consists of calcite and the pearl layer is usually composed of aragonite. The opinion that prismatic pearls are calcite structure has been accepted by many papers in general. The X ray results from our study on the shell and prismatic pearl diffraction show that (1) all pearl layer is aragonite structured, with exception of oyster shells, which comply with the above theory; (2)Prismatic layer is almost composed of all aragonite structure, only the prismatic layers of oyster shell and Pinna atropurpurea Sowerby shell are calcite structure, which basically reject the above theory; (3) Periostracum consists of organic matter conchiolin and calcite or aragonite, and some also contains silica and other impurities, which do not entirely agree with the above theory; (4) The conclusion that prismatic pearl is all aragonite structure proposed by Kobayashi Shinjiro is proved to be fault as results.