The gemological institute of america recognizes two grades in the imperfect category .

美国的宝石学院确认两职类不完善.

Mr. yang serves on the university of san diego business school board of advisors and gemological institute of america board of governors .

杨先生任职于圣迭戈大学商学院顾问委员会和美国宝石研究所理事会。

An independent , third-party gemstone grading report , such as from the gemological institute of america .

一份第三方独立宝石评级机构（比如美国宝石学院）的报告。

According to the gemological institute of america , up until 1896 , india was the only source of diamonds .

根据美国某某机构，直至1896年，印度是世界钻石的唯一来源。

Room temperature conditions are adequate for gemological purposes , as the small difference in density of the water will have little effect on the readings ( measured to the second decimal ) .

测试宝石室温条件是足够的，对水的密度而言会有小的差异，但对读数而言影响不大（测量至小数二位）。