About the problems of the nucleus that were made of Dobugai shellfish and Giant Clam

Abstract

I discuss about the difference of the nacre structure and intersection board structure that are the main structure of each shell.
I test the physical properties such as specific gravity, hardness, fluorescence, and magnetism rate.
With the identification method that depends on these differences, I mention each method on the nucleus and the pearl, furthermore I discuss the accuracy based on a destruction test.
I discuss about the issue of the nucleus made of Giant Clam from the influence of Washington Convention, passing year change, and brilliance.