DES – AGIL 2018/19 International Gemmological Conference Speaker - Andrew Cody




Andrew Cody

Title of Presentation

The Classification of Opal



The professional biography:

Andrew started collecting fossils, minerals, and gemstones at 12 years of age. He began cutting opal in 1964 after a school excursion to Coober Pedy. In 1971, he established a wholesale opal and gem cutting business, which expanded to include exporting to Europe, Japan and USA.


His industry achievements include involvement in the proclamation of Opal as Australia’s National Gemstone, the production of an award-winning Opal stamp series with Australia Post, the design of the official National Gemstone emblem and development of the official Opal Nomenclature.


In 1991 Andrew wrote, “Australian Precious Opal – a Guide Book for Professionals” this was published in English and Japanese and used extensively worldwide by the industry.


In 2010 Andrew and his brother Damien published “The Opal Story” in six languages, there are now more than 50,000 copies in circulation.


Andrew is joint founder and director of "The National Opal Collection" (NOC) with showrooms and Museums in both Sydney and Melbourne. His opalised fossil collection is expansive and includes a 2.5 metre opalised pliosaur, and the opalised upper jaw of a rare mesozoic mammal.


Andrew’s businesses are winners of both Government Export and Tourism Industry Awards. He has a Gold Commendation from the Lord Mayor of Melbourne and is a Research Associate of The Australian Museum.


He has served the Industry in a number of official capacities including President of the Australian Gem Industry Association, Founding Member and Chairman of the Australian Jewellery and Gemstone Industry Council, a special projects officer of CIBJO (The World Jewellery Council).


He is a member of Thailand’s JTC-AIGS Leaders Council (JALC), and Past President of The International Colored Gemstone Association.


He is an Honorary Fellow of both the Australian Gemmological Association and The Gemmological Association of Great Britain, and is a regular speaker at international forums, he has a true passion for his industry and has now been involved with opal for more than 50 years.


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