香港大學地球科學系–亞洲寶石學院 2018國際寶石學研討會主講嘉賓–Andrew Cody

DES – AGIL 2018 International Gemmological Conference
香港大學地球科學系–亞洲寶石學院 2018國際寶石學研討會

DES–AGIL 2018國際寶石學研討會
日期:2018年9月16日 (星期日)
時間:上午9時至下午12時半
地點:香港大學道3號香港大學
           研究生堂王賡武講堂
語言:英語及普通話即時傳譯
DES–AGIL 2018 International Gemmological Conference
Date :   16th September 2018 (Sunday)
Time :   9:00am – 12:30pm
Venue : Wang Gungwu Lecture Hall, Graduate House,
The University of Hong Kong, 3 University Drive, Hong Kong
Language: English & Mandarin Simultaneous Translation

 

 

 

Speaker Andrew Cody
Title of Presentation The Classification of Opal

 

The abstract of the talks
Twenty years ago an official opal classification and nomenclature was developed in Australia
Opal is a large and diverse gemstone family. Unlike most other gemstones Opal types will range in appearance, hardness, specific gravity, refractive index, water content and some are absorbent.
Today, the Gemmological Association of Australia together with the Australian Opal Association joint committees are working closely with other Australian stakeholders to provide recommendations for a universal opal classification.
This presentation will cover the reasons for changes to classification and will give the audience an in-depth understanding of Opal Classification and the factors that determine value.
The Gemmological Association of Australia last year established an opal subcommittee to create an online opal course. The Australian Opal Association also created a subcommittee to review the existing classification and nomenclature. After several meetings the two groups agreed to collaborate to establish a basic structure for the revised classification.
The joint committees are also planning to work closely with other Australian stakeholders so as to provide recommendations for a system of opal classification, nomenclature and associated definitions that can be put forward to the international community for consideration. Although there are still some reservations considerable progress has been made and the committees have agreed to eight categories of opal as illustrated in the flow chart below


CLASSIFICATION
Classification is the categorization of opal according to specific factors into Class, Category, Type and Variety, using defined Nomenclature.