LMHC Laboratory Manual Harmonisation Committee, finalizes four new information sheets, reports good progress on harmonisation of gemstone report wording
GAA Magazine Vol 12, Issue 11, Nov/Dec 2011.

CIBJO - The World Jewellery Confederation - Gemstone Blue Book 2010-11.

A definitive set of standards outlining the grading, methodology and nomenclature standards for coloured gemstones. The CIBJO Blue Books (also cover diamonds, pearls, precious metals, gemmological terminology and nomenclature) were compiled and updated, by a number of committees, with representatives from trade organizations and laboratories.The standards represent a consensus derived from the broad expertise within the committees, and interested individuals outside the committees who helped in the development of the guidelines.

A guide produced by the Opal Association Inc., the base body tone refers to the darkness of the Opal ignoring the play of colour and brightness of the stone.

PLAY-OF-COLOR IN OPAL FROM WEGELTENA, WOLLO PROVINCE, ETHIOPIA. From Gems & Gemmology Summer 2010 Edition. Contributors:Benjamin Rondeau, Emmanuel Fritsch, Francesco Mazzero, Jean-Pierre Gauthier, Bénédicte Cenki-Tok, Eyassu Bekele, and Eloïse Gaillou

‘Sphere Packing in Opal’ by Paul Thomas, UTS – School of Chemistry & Forensic Science. Delivered at the 7^th National Opal Symposium held at Lightning Ridge in July 2011.

‘Water in Opal’ by Nicole McGowan, UTS – School of Chemistry & Forensic Science. Delivered at the 7^th National Opal Symposium held at Lightning Ridge in July 2011.

By S.V.Filin, A.I Puzynin Dubna, JINR, Russia. In The Australian Gemmologist, October-December 2009. Vol.23, No.12.

Gemmological properties,micro- and nano-structures. By Tay Thye Sun, Puah Chun Mok, Sunny Liew Paul, Mahardi Paramita, Charles E.S.Arps, Wilawan Atichat, Emmanuel Fritsch, We Weng Kang and Kumala Wijaya.

In The Australian Gemmologist, July-September 2009, Vol 23, No.11.

By Grant Pearson in The Australian Gemmologist, April-June 2010, Vol.24, No.2.

A 10 page article by Anthony Smallwood in Australian Gemmologist 2003, Vol.21.

By Anthony Smallwood (FGAA,GG), in Australian Gemmologist 1997, 19.

National Council of Jewellery Valuers - 'Valuer' magazine Vol.21, No.2 April/June 2003. Article by Anthony Smallwood.

Brochure published by the Jewellery Association of Australia.

What is an Opal? - Single page flyer produced by the Australian Opal & Gem Industry Association.