35th IGC 2017 Windhoek, Namibia

IGC 2017 Windhoek
Location and Working Hours
11. Oct 15. Oct. 2017

IGC 2017: Windhoek, Namibia

Dear colleagues of IGC,

It is our great pleasure to host the 35th International Gemmological Conference in Windhoek, Namibia.

The spectacular 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 Conference in Namibia. From the left: Andreas Palfi, Ruth Palfi, Ulrich Henn, Annamarie Peyer, Henry A. Hänni at Okapuka Ranch, Namibia in 2016.


Safari Hotels
Windhoek (Namibia)

Friday 13rd October

8.00 – 8.45 Executive Committee (EXECO) Meeting, Flamingo Room No. 2, Safari Hotel

Session 3 Corundum – Chairman: Karl Schmetzer

9.00 – 9.20 Terrence Coldham: An Examination of the Morphology of Grains of Crystalline Corundum from Lava Plains Northern Queensland; A Rare Example of an “in situ” Pyroclastic Sapphire Deposit

9.20 – 9.40 Franck Notari, Emmanuel Fritsch, Candice Caplan, Thomas Hainschwang: Are Boehmite Needles in Corundum Rose Channels?

9.40 – 10.00 Shane F. McClure: Sapphire Mining in Montana

10.00 – 10.20 W. Atichat, J. Jakkawanvibul, M. Maneekrajangsaeng, T. Sripoonjan, T. Leelawatanasuk, V. Pisutha-Arnond, N. Narudeesombat, P. Chanthayod, B. Sriprasert: Padparadscha Color Grading for Gem Trade

10.20 – 11.10 Coffee Break

Session 4 Diamond – Chairman: Emmanuel Fritsch

11.10 – 11.30 Hiroshi Kitawaki, Kentaro Emori, Mio Hisanaga, Masahiro Yamamoto: Two Kinds of Synthetic Diamonds Having Features Similar to Natural Diamonds

11.30 – 11.50 R. Serov, Y. Shelementiev, A. Serova: Hybrid Diamonds: Natural Diamonds Overgrown with CVD Synthetic

11.50 – 12.10 Rainer Schultz-Güttler: Skins, Stains, Spots and Ruts: Green Diamonds from Brazil

12.10 – 12.30 Andy H. Shen, Tay Thye Sun, Ye Luo, J.T. van Gorsel, Mega Rosana Fatimah, Tay Kunming, Wilyanto Deng: Kalimantan Diamonds from Landak: Gemmological Characteristics, FTIR and Photoluminescence Spectroscopy

12.30 - 14.00 Lunch at Welwitschia Restaurant, Safari Hotel

14.00 - 17.00 Poster Session Exhibition and sale of Namibian minerals and gemstones by small-scale miners, gemstone auction, Namibian jewellery exhibition Organized by Industry Growth Strategy (IGS) for the Gemstone and Jewellery Industry of Namibia

18.30 – 22.00 Dinner at Joe’s Beerhouse, Windhoek

Saturday 14th October

Session 5 Spinel, Tourmaline, Garnet – Chairman: Gamini Zoysa

9.00 – 9.20 Jayshree Panjikar, Aatish Panjikar: Study and Investigation of Spinel from Kermunda in Odisha, India

9.20 – 9.40 Cheng-Si Wang, Andy H. Shen: Reversibility of Photoluminescence Spectra of Spinel with Heat Treatment

9.40 – 10.00 Claudio C. Milisenda, Stefan Müller: REE Photoluminescence in Paraìba Type Tourmaline from Mozambique

10.00 – 10.20 Karl Schmetzer, H. Albert Gilg, Ulrich Schüssler, Jayshree Panjikar: Origin Determination of Garnets: Search for Historical Trade Routes

10.20 – 11.10 Coffee Break

Session 6 Corundum – Chairlady: Willow Wight

11.10 – 11.30 J.C. (Hanco) Zwaan, Leo M. Kriegsman, Jorien L.N. van der Wal, Richard J.M. Taylor, E. Gamini Zoysa: Characterization and Formation of ‘Metamorphic’ Sapphires – Examples from Sri Lanka

11.30 – 11.50 E. Zoysa Gamini, Liu Shang I, Edward, Arūnas Kleišmantas: Preliminary Report on New Corundum Deposits of Sri Lanka

11.50 – 12.10 Sutas Singbamroong, Aisha Rashid Almazrooei, Nazar Ahmed: Lead Glass-Filled Padparadscha

12.10 – 12.30 Seung Kwon Lee, Kiran Kwon: Raman Study for Heat-Treated Sapphires Based on the Structural Relaxation by Impurities and Thermal Energy

12.30 - 14.00 Lunch at Welwitschia Restaurant, Safari Hotel

Session 7 Investigation Techniques – Chairman: Hanco Zwaan

14.00 – 14.20 Michael. S. Krzemnicki, Hao A. O. Wang, Walter A. Balmer, Jean-Pierre Chalain, Pierre Lefèvre, Wei Zhou, and Laurent Cartier, Henry A. Hänni: GemTOF: A New and Highly Versatile Method to Analyse Trace Elements and Isotopes of Gemstones and Pearls

14.20 – 14.40 Kentaro Emori, Hiroshi Kitawaki: Identification of Natural and Synthetic Amethyst Using Multivariate Analysis

14.40 – 15.00 Masaki Furuya: The Efficiency and Limitation of the Phosphorescence Imaging for Screening Current Melee Sized Synthetic Diamonds

15.00 – 15.20 Bahareh Shirdam, Soheila Aslani: Origin determination of Iran Excellent-Quality Turquoise Based on Trace Element Analysis Using ICP-MS and Micro XRF 35th IGC 2017 – Windhoek, Namibia 11 C

15.20 – 15.50 Coffee Break 15.50 Poster Session 19.00 – 22.00 Gala Dinner at Omatako Room 2, Safari Court Conference Centre

Sunday 15th October

Session 8 Pearls and Amber – Chairman: Tay Thye Sun

9.00 – 9.20 Nick Sturman, Areeya Manustrong, Kwanruen Lawanwong, Promlikit Kessrapong, Nanthaporn Somsa-ard, Artitaya Homkrajae: “Golden” Pinctada Maxima Non-Bead Cultured Pearls with an Emphasis on their Internal Structures

9.20 – 9.40 Stefanos Karampelas, Abeer Tawfeeq Al-Alawi, Ali Al-Attawi, Kenneth Scarratt: Natural Pearls Found from Pinctada Radiata in the Kingdom of Bahrain: Characteristic Structures, Comparison and Identification

9.40 – 10.00 Elisabeth Strack: Past and Present Situation of Freshwater Pearls from North Western Russia

10.00 – 10.20 Liu Shang I, Edward: Feather and Insect Inclusions in Burmese Amber and its Impact on Origin Determination

10.20 – 10.50 Coffee Break

Session 9 Miscellaneous – Chairman: John Saul

11.10 – 11.30 Willow Wight: Ammolite, Canada’s Unique Fossil Gemstone

11.30 – 11.50 Anette Juul-Nielsen, Arent Heilmann: A Gemstone Occurrence Map for Greenland

11.50 – 12.10 Stephen Kennedy, Jens Najorka: Imitations of Tianhuang and Shoushan sSones

12.10 – 12.30 Çiğdem Lüle: Gemological Terminology issues: An Ongoing Battle…

12.30 - 14.00 Lunch at Welwitschia Restaurant, Safari Hotel Session 10 Beryl, Cordierite, Jade – Chairman: Ulrich Henn

14.00 – 14.20 Klaus Schollenbruch, Lore Kiefert, Klemens Link, Tewodros Sintayehu: Gem Quality Emeralds from Ethiopia

14.20 – 14.40 Karen E. Fox, Chris Yakymchuk: Canadian Gem-Grade Cordierite

14.40 – 15.00 Ahmadjan Abduriyim, Kazuko Saruwatari, Yusuke Katsurada: Jadeite Jade from Japan: Its History, Gemmology and Comparison with Jadeite from other Sources

15.00 – 15.40 Coffee Break

15.40 – 16.40 Closing Ceremony, Namib Room 1, Safari Hotel

19.00 – 21.00 Buffet Dinner at Acacia Restaurant, Safari Court Hotel


  • Daniel Barchewitz: GemRam for Simple Gem ID
  • Laurent E. Cartier, Michael S. Krzemnicki, H.A.O. Wang, Henry A. Hänni: Traceability of Gemstones: Challenges and Opportunities
  • Gagan Choudhary: AquapraseTM: An Interesting Green-Blue Variety of Chalcedony
  • Henry A. Hänni, Leander Franz, Wei Zhou: Sannan-Skarn: a New Ornamental Gemstone from Pakistan
  • Arūnas Kleišmantas, Gamini E. Zoysa, Edward Liu Shang I: Chemistry and Gemmological Features of Spinels from Sri Lanka and Vietnam
  • Michael Krzemnicki, Hao A. O. Wang, Tom Stephan, Ulrich Henn: Cobalt Diffusion-Treated Spinel
  • Leander Franz, Michael Krzemnicki, Kristina Ernst, Christian de Capitani, George E. Harlow, Nicolai Kouznetsov: Kosmochlor-Bearing Jadeite Rocks from Kenterlau-Itmurundy (Lake Balkhash, Kazakhstan)
  • Thanong Leelawatasuk, Tasnara Sripoonjan, Namrawee Susawee, Pornsawat Wathanakul, Visut Pisutha-Arnond: Rare Fancy Sapphires from Bo Phloi Gem Field, Kanchanaburi, Western Thailand
  • Thanapong Lhuaamporn, Saengthip Saengbuangamlam, Nataya Nilhud, Thanong Leelawatanasuk: Characteristics of Exceptionally Gem-Quality Untreated Blue Sapphires from Bo-Phloi Gemfield, Kanchanaburi-Thailand
  • John M. Saul: Transparent Gemstones and the Most Recent Supercontinent Cycle
  • Andy H. Shen, Cuihong Liu, Tian Shao, Min Ye: Color Origin of Color-Changing Diaspore from Turkey
  • Jian Mao, Elizabeth Su: Research of Jadeite Inclusions: Graphite and Zircon
  • Panjawan Thanasuthipitak, Kanyarat Kwansirikul, Weerapan Srichan, Phisit Limtrakun, Opor Saidum and Theerapongs Thanasuthipitak: Gem Materials from Upper Northern Thailand: Potential in Jewellery