The 28th International Gemmological Conference, Madrid, Spain.
The followings are the topic discussed by various members.

Diamond
No. Title Authors
1. Diamonds from the eastern offshore of Phuket Island, Thailand P.Wathanakul, S. Nakapadungrat,
S. Sakkaravej and P. Lomthong
2. Diamonds in Canada - an update A.A. Levinson
3. Origin of irregular shapes of natural type II diamonds I. Sunagawa
4. Natural and HPHT annealed pink and blue diamonds G. Bosshart
Coloured stones - Ruby, Sapphire
No. Title Authors
5. Sapphires and rubies from the Ruvuma (Tunduru and Songea), Lindi (Liwale) and Mtwara (Mbekenyera) districts in Southern Tanzania. D. Schwarz
6. The sapphirine-ruby connection: new occurrence in an ornamental rock named “tutti frutti” B. Lasnier, C. Simonet
7. Young and old sapphires Australia – SE Asia F.L. Sutherland, R.R.Coenraads, C.M. Fanning, P.Hoskin.
8. Sapphires from Phrae-Sukhothai Gemfield, Northern Thailand. P. Wathanakul, W. Atichat.
9. A preliminary study of sapphire from Myanmar. Tay Thye Sun, U. Tin Hlaing, Wilawan Atichat, Win Win Thar, S.M.Tang
10. Gemmological study of corundum of Madagascar J. Shida
11. Gemmological characterization of the magnetic properties of sapphires N.L.E.Haralyi, G. Bosshart
12. Luminiscence of a-Al2O3 and a-AlOOH natural mixtures J. Garcia Guinea, Correcher, V.
Emerald
No. Title Authors
13. The Itabira Emerald field. J. Kanis
14. Preliminary study of emeralds from the Piteiras emerald mine, Minas Gerais, Brazil. J.C. Zwaan
15. Steps on the route of identification of archaeological emeralds origin. C.Aurisicchio, L.Martarelli, S.Nunziante Ceasareo, G. Grazianni
16. Emeralds of the Ural mountains (Russia): Geology, fluid inclusions and oxygen isotopes. e.Gavrilenko, g. Giuliani, M.Popov, Ch. France-Lanord
Coloured Stones - Jade
No. Title Authors
17. Classification of Myanma jadeite jades and their infrared spectra. C.M.OuYang and X.Yuan
18. The Hkamti Jadeite mines area, Sagaing Division, Myanmar. R.E.Kane
19. The colour-causing mechanism of lavender jadeite-jade. x.Yuan, G. Du
Coloured Stones - Garnet, etc.
No. Title Authors
20. Demantoid garnet around the world. C.C.Milisenda
21. Malaya garnets from Madagascar. K. Schmetzer, T. Hainschwang, L. Kiefert, H.J.Bernhardt.
22. Gem peridots in the world and peridots from two sources in China. A. Chikayama
23. The peculiarity of the olivine from Sri Lanka G. Graziani, L. Martarelli, E. Gamini Zoysa.
24. Transparent green orthoclase, a new amazonite-type ornamental stone from South East Asia. J. Ponahlo, T. Thi Tham, F. Brandstatter, H. Wildner
25. Mexican gem opals: Nano and micro-structure, origin of colour, and comparison with the other common opals of gemological significance. E. Fristsch, M. Ostroumov, B. Rondeau, A. Barreau, D. Albertini, A.M. Marie, B. Lasnier, J. Wery
26. Recent researches at CISGEM M. Superchi, A. Donini, E. Gambini, D. Muzzioli
27. Sparks Gem rush at Ilakaka deposits in Madagascar M. Furuya, A. Chikayama
Organic Gem Materials, Synthetics, Treatments and Imitations.
No. Title Authors
28. Mabe pearls from northern Queensland, Australia G. Brown
29. Ojime make of tooth of grass eating animals I. Sunagawa, Y. Takahashi, I.Kimura, T. Sakae
30. Recent observation of composite stones U. Henn
Regional Gemmology
No. Title Authors
31. Spanish gemstone deposits: post-conference tour. C. Sapalski, J. Garcia Guinea
32. Gemstone of Peru. J. Hyrsl
Gemmologic techniques and equipments, Miscellaceous
No. Title Authors
33. Application of some laboratory methods to the study of gemstones J.M. Dereppe, C. Moreaux
34. Hardness testing of gemstones: A re-evaluation of the values M. Gray
35. Archaeological and gemmological survey of Vatican Museums’s, Etruscan and Roman Jewellery (VII B.C. to III Century A.D.) C. Aurisicchio, L. DiGiulio, S. Ehrman, G. Graziani, M. Sannibale