An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-colour.
Read MoreThis section, from the Winter 2011 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Spring 2003 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Spring 1994 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Autumn 1995 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Summer 1987 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Winter 1995 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Autumn 1988 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreThis section, from the Spring 1998 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
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