35 TH IG C 2017 INTERNATIONAL GEMMOLOGICAL CONFERENCE NAMIBIA October 8 - 19, 2017 Namibia IGC 2017 N 35 TH IG C 2017 INTERNATIONAL GEMMOLOGICAL amibia CONFERENCE NAMIBIA October 8 - 19, 2017 Namibia www.igc-gemmology.org 35th IGC 2017 – Windhoek, Namibia Introduction 35th International Gemmological Conference IGC October 2017 Windhoek, Namibia Dear colleagues of IGC, It is our great pleasure to host the 35th International Gemmological Conference in Windhoek, Namibia. The spectacu- lar landscape, the species-richness of wildlife and the variety of cultures and traditions make Namibia a very popular country to visit. For gemmologists Namibia is of highest interest because of its unique geology, mineral resources and gemstone potential. IGC is an important platform for distinguished gemmologists from all over the world to present and discuss their latest research works but also to cultivate friendship within the gemmological family. It is our great desire to thank the local organizer Andreas Palfi for his extraordinary work to realize the IGC in Namibia. The organizers of 35th International Gemmological Conference wish you an exciting and memorable conference. Dr. Ulrich Henn, Prof. Dr. Henry A. Hänni, Andreas G. Palfi MSc The organizers of the 35th International Gemmological Confe- rence in Namibia. From the left: Andreas Palfi, Ruth Palfi, Ulrich Henn, Annamarie Peyer, Henry A. Hänni at Okapuka Ranch, Namibia in 2016. 1 35th IGC 2017 – Windhoek, Namibia Introduction Organization of the 35th International Gemmological Conference Organizing Committee Dr. Ulrich Henn (German Gemmological Association) Prof. Dr. Henry A. Hänni (Swiss Gemmological Institute SSEF) Andreas G. Palfi MSc (local organizer, Consulting Exploration Geologist, Palfi, Holman and Associates, Geo Tours Namibia and Namibia Minerals) Dr. Jayshree Panjikar (IGC Secretary) IGC Executive Committee Guest Programme Ruth Palfi (Windhoek, Namibia) and Annamarie Peyer (Hong Kong) Homepage Dr. Michael Krzemnicki (Swiss Gemmological Institute SSEF) Dr. Laurent Cartier (Swiss Gemmological Institute SSEF) Proceedings Dr. Michael Krzemnicki (Swiss Gemmological Institute SSEF) Dr. Laurent Cartier (Swiss Gemmological Institute SSEF) Abstract Review Board Prof. Dr. Henry A. Hänni Prof. Dr. Emmanuel Fritsch Dr. Ulrich Henn Dr. Karl Schmetzer Dr. Hanco Zwaan Special thanks Mrs. Martina Bank (German Gemmological Association) for organizing registrations, general administration and financial management. Acknowledgements Ministry of Mines and Energy Namibia: The Honourable Minister Obeth Kandjoze, MP The Honourable Deputy Minister Kornelia Shilunga, MP Permanent Secretary Simeon Negumbo Mining Commissioner Mr. Erasmus Shivolo Department Geological Survey: Ms. Gloria Simubali, Acting Deputy Permanent Secretary Chamber of Mines of Namibia: Mr. Veston Malango CEO Green Dragon Mine: Mag. Stephan Reif Kristall Gallerie and Otjua Tourmaline Mine: Kleynhans family Usakos Tourmaline Mine: Mr. Hannes Brunner Namibia Diamond Trading Company (NDTC): Mr. Shihaleni Ndjaba CEO Namdeb Diamond Corporation: Mr. Riaan Burge, General Manager and Dr. Jurgen Jacob, Head of Mineral Resource and Environment Namcot Diamonds: Mr. Ofer Babluky, General Manager 2 35th IGC 2017 – Windhoek, Namibia Introduction About the IGC Executive Committee Dr. Jayshree Panjikar, Executive Secretary, India (fourth from the left) Prof. Dr. Emmanuel Fritsch, France (first from the left) Dr. J. C. Hanco Zwaan, The Netherlands (second from the left) Tay Thye Sun, Singapore (third from the left) Prof. Dr. Henry A. Hänni, Switzerland (fourth from the right) Dr. Karl Schmetzer, Germany (third from the right) Gamini Zoysa, Sri Lanka (second from the right) Willow Wight, Canada (first from the right) Members of the IGC Executive Committee at the Closing Dr. Michael Krzemnicki, Switzerland Ceremony of the 34th IGC in Vilnius, Lithuania. Dr. Dietmar Schwarz, Germany About the venue Windhoek Windhoek is the capital of the Republic of Namibia and located at the geographical centre of the country. More than 320,000 people live in Namibia’s largest city which is the social, economic, political and cultural centre. Windhoek Windhoek downtown The conference will be held at the Safari Hotels with well-equipped conference facilities. Pre- and post-conference tours will lead to the diamond operations at Oranjemund and near Lüderitz and to tour- maline and garnet mining areas near Karibib and Usakos as well as to the historic place Swakopmund at the Atlan- tic Ocean with its unique museum and Kristall Gallerie. Safari Court Hotel Otjua Tourmaline Mine Sponsors Your Mobile Spectroscopy Partner 3 35th IGC 2017 – Windhoek, Namibia Introduction INTERNATIONAL GEMMOLOGICAL CONFERENCE History of the IGC The International Gemmological Conference (IGC) owes much of its origin to BIBOA (Bureau International pour la Bijouterie, Orfevrene, Argenterie), the International Jewellery and Gemstone Federation, the first Congress of which in 1926 recommended and defined use of the term cultured pearl. Experts from various European gem testing laboratories were invited to attend a series of expert meetings that aimed to formulate the policies of BIBOA. In 1936, at the fifth conference of experts, collaboration among laboratories was acclaimed by traders and they encouraged Laboratory Directors to meet each other at a technical conference from which all commercial delegates would be excluded. Technical meetings were held annually, and in 1951 a Technical Conference was held in Idar Oberstein to prepare for the next London Congress in 1952. Those attending the 1951 conference included Mr B.W. Anderson, Mr G. Gobel, Dr E. Gübelin, Mr F. Wolf, Mr A. Bonebakker, Mr H. Tillander, Mr A. Strondahl, and Mr O. Dragstead. It has been suggested that the future framework of the IGC was established at this meeting in Idar Oberstein. The London Congress saw the restructuring of BIBOA in which Gemmological Associations were replaced by National Federal Committees, and BIBOA evolved into BIBOAH – the forerunner of CIBJO, now known as The World Jewellery Confederation. A Technical Conference met at Lugano from 23rd to 25th October 1952 at the initiative of Prof. K. Schlossmacher and Dr. E. Gübelin. Also present at this conference were Messrs B.W. Anderson, A. Bonebakker, O. Dragstead, G. Gobel, K. Siess and H. Tillander. At this historic meeting Dr E. Gübelin proposed creation of a “Committee of an International Gemmological Association” that would consist of one member per country; this member being the Director of a Gem Testing Laboratory, or a gemmologist of the calibre who could attend that meeting. This was agreed to, and this mee- ting was later considered to be the inaugural meeting of the IGC. The first meeting of the IGC in Lugano was followed by subsequent meetings in Amsterdam, The Netherlands (1953), Copenhagen, Denmark (1954), London, UK (1955), Munich, Germany (1956), Oslo, Norway (1957), Paris, France (1958), Milano, Italy (1960), Helsinki, Finland (1962), Vienna, Austria (1964); Barcelona, Spain (1966); Stockholm, Sweden (1968); Brussels, Belgium (1970); Vitznau, Switzerland (1972); Washington D. C., USA (1975), The Hague, The Nether- lands (1977), Idar Oberstein, Germany (1979), Kashiko-Jima, Japan (1981), Beruwela, Sri Lanka (1983); Sydney, Aus- tralia (1985); Rio de Janeiro, Brazil (1987), Tremezzo, Italy (1989); Stellenboch (1991), Paris, France (1993); Bangkok, Thailand (1995); Idar Oberstein, Germany (1997); Goa, India (1999); Madrid, Spain (2001), Wuhan, China (2004); Mos- cow, Russia (2007); Arusha, Tanzania (2009), Interlaken, Switzerland (2011); Hanoi, Vietnam, (2013); Vilnius, Lithuania (2015); the 35th IGC will be held in Windhoek, Namibia in 2017. Over the history of the IGC, that now in its fourth decade, it can therefore be seen that the International Gemmolo- gical Conference is the longest surviving gemmological conference to remain largely in its original format. Over its history, invited delegates representing 33 countries or areas – including Australia, Austria, Belgium, Brazil, Canada, China, Czech Republic, Denmark, England, Finland, France, Greece, Germany, Hong Kong, Israel, India, Italy, Japan, Kenya, Korea, Netherlands, Norway, Russia, Singapore, South Africa, Spain, Sri Lanka, Switzerland, Sweden, Thailand, U.S.A. and Zimbabwe – have been invited to participate in IGC meetings. 4 35th IGC 2017 – Windhoek, Namibia Introduction During the 20th IGC, which was held in Sydney, Australia, the members present elected nine members to Honorary Members status. The first Honorary Members of the IGC were Oliver Chalmers (Australia), Prof. A. Chikayama (Japan), and Mr R. Crowningshield (U.S.A), Mr. O. Dragsted (Sweden), Prof. Gübelin (Switzerland), Mr. R. T. Liddicoat (U.S.A), Mr. M. Masso (Spain), Dr. F. H. Pough (U.S. A) and Dr. J. M. Saul (Kenya). In Italy, the IGC logo was designed by Roberto Sambonet and made in gold by Roberto Cusi offered to the conference delegates during the Tremezzo 1989. In Italy, in 1989, the following rules were agreed for future meetings of the IGC: 1. The prime objective was to be the exchange of gemmological experiences. 2. Gemmology was to be the platform for all topics and was to be regarded as the principal theme. 3. It was decided that attendance at all further Conferences should be by invitation that would be determined where necessary by the Conference Secretary and the Executive Committee. 4. All delegates were to be encouraged to present papers; but this would not be mandatory. 5. All delegates must have