No.5 November 2007 GEM QUALITY JOHACHIDOLITE: OCCURRENCE, CHEMICAL COMPOSITION AND CRYSTAL STRUCTURE MESSAGE Editor Message from the Editor’s Desk Dr. A. Peretti, FGG, FGA, EurGeol GRS Gemresearch Swisslab AG, P.O.Box 4028, The continuous research on new gem occurrences 6002 Lucerne, Switzerland and new gemstones is a very important aspect of [email protected] the activities of a modern gemological laboratory. With the description of a revised crystal structure Previous Journals of painite in our previous publication and the description of the new gem mineral pezzottaite, GRS has invested much in this tradition. It has featured its discoveries in two issues of Contribution to Gemology No. 2 and No. 3 and published the detailed results in American Mineralogist and Mineralogical Record (see literature). Research institutions all over the world, some of them considered the most prestigious in this field of research such as Caltech University, have made links to the online version of our journal at www.gemresearch.ch, particularly suitable for students to appreciate our extensive use of illustrations. Every day several thousand visitors search our website from more than 15 countries, confirming the interest in rare collector gems in the gem community and the public. It took GRS and its collaborating scientific partners in Switzerland almost two years of intensive research to make another important discovery of corresponding caliber. Again, it is a discovery in the field of new gem occurrences and new important data on mineral structures and mineral chemistry. This time the news is not coming from new mines in Madagascar but from the famous valley of Mogok in Burma, renowned for its fabulous rubies and sapphires. As we constantly studied the ruby and sapphire mines in Mogok, it was only a matter of time to discover one of the rarest collector gems in the world: Johachidolite. It is a true gem with its vivid color, high brilliancy due to the high refractive index, This journal follows the rules of the Commission on high density and Mohs hardness of over 7.5. New Minerals and Mineral Names of the IMA in all matters concerning mineral names and nomenclature. Careful crystallographic examination of johachidolite enabled a state of the art structure refinement, Distributor which will be additionally published in a specialized scientific journal of high recognition. Thorough GRS (Thailand) Co., LTD 257/919 Silom Rd., JTC Building examination of the chemistry of johachidolite Bangkok 10500, Thailand. provided us with data elucidating its origin and authenticity. A new rare earth element (REE) Journal and Website Copyrighted by GRS (Thailand) “fingerprint test” for the origin of johachidolite has Co. LTD, Bangkok, Thailand and GRS Gemresearch been made available with the publication of this Swisslab AG, Lucerne, Switzerland new edition of “Contribution to Gemology No. 5”. This report is available online at www.gemresearch.ch ISBN 978-3-9523359-3-2 Adolf Peretti Gem Quality Johachidolite: Occurrence, Chemical Composition and Crystal Structure Gem Quality Johachidolite: 1 Details of Mining Activities at the 13 Occurrence, Chemical Composition “Johachidolite-Hill” Mine at and Structure Pyant Gyi 0’ O 23 GEM OCCURRENCES AT PYANT GYI Mining Activities for Johachidolite 14 59’ O Painpyit 22 Pain Pyit ydef;jypf Pyant Gyi Sapphire Province jyefH[uD; Origin of Johachidolite 2 at the Pyant Gyi Mine JOHACHIDOLITE 58’ O OCCURRENCE 22 N-22o 58’ 20.8” E-96o 32’ 54.0” (1459 m) Dat Taw gwfawmfX Painpyit Pain Pyit Sapphire New Discovery of Johachidolite: Petrography of Pegmatite Province 3 15 JOHACHIDOLITE OCCURRENCE Dat Taw Geology Containing Johachidolite Leu-Dattaw Ruby Province LEU OHN BIN Library of Raman Spectra of 16 Rock Forming Minerals of the New Discovery of Johachidolite to 4 “Johachidolite-Pegmatite” the North-East of Mogok Petrography of 17 Johachidolite-Bearing Pegmatite New Discovery of Johachidolite: and Inclusion in Johachidolite Kyauk Sin 5 Myeme Kolan Geological Map and Cross Section of the Mogok Belt Inclusion in Johachidolite 18 H Analyses of 3-phase Fluid 19 The Neighboring Ruby Deposits at 6 Inclusions in Johachidolite Kadottat and Baw Pa Dan Fluid Inclusion in Johachidolite 20 Visiting the Ruby and Spinel Mines 7 Inclusion Features in Johachidolite 21 of Pain Pyit in 2002 Studying the Mineral Occurrences 8 in Chaung Gyi in 2002 Petrography of 22-23 Johachidolite-Bearing Pegmatite Danburite Orthorhombic Gemological Chart of Gem CaB2Si2O8 9 Hackmanite Cubic Na8Al6Si6O24(Cl2, S) Johachidolite Orthorhombic CaAl(B3O7) Occurrences at the Poudretteite Hexagonal KNa2BSi12O30 Pyant Gyi Mine Johachidolite Gem Materials 24 Catalogue of Gems from 10 Pain Pyit Area and Pyant Gyi Mine Gem Set of Johachidolite and 25 Rare Johachidolite Crystal Panorama View from the 11-12 Physical and Optical 26 “Johachidolite-Hill” mine Properties and UV-Fluorescence (Pyant Gyi) towards Pain Pyit of Johachidolite Contents of Contributions to Gemology No.5 Electron Microprobe Analysis: 27 LA-ICP-MS Chemical Analyses 39 Methods of Fluorapatite LA-ICP-MS and EMPA Chemical 28 LA-ICP-MS Chemical Analyses of 40 Analyses of Johachidolite Hackmanite, Scapolite, Orthoclase and Fluorapatite Classification of Johachidolite 41 LA-ICP-MS Chemical Analysis of 29 Classification of Johachidolite, 42 Johachidolite (Continued) Fluorapatite and Scapolite Using REE-Patterns FTIR and Raman Spectroscopy of 43 LA-ICP-MS Chemical Analysis: 30 Johachidolite Methods Raman Spectrum of Johachidolite 44 LA-ICP-MS Chemical Analyses of 31 Johachidolite UV/VIS Spectroscopy of 45 Johachidolite Chemical Analyses of Johachidolite 32 and Accompanying Minerals Origin of Color in Johachidolite 46 Crystal Structure and 47 LA-ICP-MS Chemical Profile 33 Crystal Chemistry Across a Color-Zoned Johachidolite Crystallography of Johachidolite 48 REE Patterns in Minerals and 34 Explanation of Europium (Eu) Crystal Structure and 49 Anomaly in Johachidolite Crystal Chemistry of Johachidolite REE Patterns in Johachidolite and 35 Crystal Structure and Crystal 50 Color-Zoning Chemistry of Johachidolite and Comparison to Okayamalite Chemical Variation in Johachidolite 36 REE-Pattern In Various Minerals 37 Poudretteite Crystal Structure 51 Accompanying Johachidolite LA-ICP-MS Chemical Analyses 52 Rare Earth Elements 38 of Poudretteite (LREE, HREE), Th, U and Be-Concentrations in Acknowledgements and Literature 53 Pegmatite Minerals Gem Quality Johachidolite: Occurrence, Chemical Composition and Crystal Structure GEM QUALITY JOHACHIDOLITE: OCCURRENCE, CHEMICAL COMPOSTION AND CRYSTAL STRUCTURE Adolf Peretti (1), Francesca Peretti (1), Ngwe Lin Tun (1), Detlef Günther (2), Kathrin Hametner (2), Willy Bieri (3), Eric Reusser (4), Milen Kadiyski (5), Thomas Armbruster (5) (1) GRS Gemresearch Swisslab Ltd, Sempacherstr.1, CH-6003 Lucerne, Switzerland (2) Laboratory of Inorganic Chemistry, ETH Hönggerberg, HCI, G113, CH-8093 Zurich, Switzerland (3) GRS (Thailand) CO LTD, Bangkok, 10500 Thailand (4) Institute of Mineralogy and Petrography, Clausiusstr. 25, ETH Zentrum, CH-8092 Zurich, Switzerland (5) Miner. Crystallogr., Institute of Geological Sciences, University of Berne, Freiestr. 3, CH-3012 Berne, Switzerland INTRODUCTION The mineral was first described, though with a wrong to locate the occurrence of new gems. The mining chemical formula, from the Johachidolite District, area, however, is closed for foreigners since 2004 and Kisshu County, Kankyo Hodu Perfecture, North Korea, even when visitors were permitted to visit the area, and was named after the type locality. Aristarain and many mines were government controlled and Erd (1977) assumed that the originally postulated inaccessible. Between 1999 and 2002, one of the composition of johachidolite H6Na2Ca3Al4F5B6O20 authors (AP) was permitted to explore the mines at (Iwase and Saito, 1942) is due to intimate intergrowth Mogok and was able to spend a total of about three of two different minerals, one F-rich and the other weeks in the field. Among important information on the johachidolite of CaAlB3O7 composition. The newly occurrence of rubies, sapphires and spinels in this proposed formula and redefinition of the mineral is area, it lead to the discovery of painite (Armbruster et based on electron microprobe analyses of the al., 2004). During the trips to the Eastern part of metatype specimen showing major Ca and Al only Mogok, special attention was paid to the mining areas (Aristarain and Erd, 1977) and a single-crystal X-ray of Pain Pyit and Chaung Gyi. These mines are study performed on the same material by Moore and normally inaccessible to visitors but permission was Araki (1972). The latter authors showed that granted in 2002 (Fig. J11 - J15). The area of Pain Pyit, johachidolite possesses an unusual layer structure in which is known as Pyant Gyi was of special interest which BO4 tetrahedra are assembled to form (Fig. J02). This area is known for the occurrence of corrugated sheets linked by octahedral Al and ten-fold various gems, such as other borates including coordinated Ca. In 2001, an article appeared with the danburite and poudretteite, as presented in Tab. J01. title “johachidolite - a new gem” (Harding et al., 1999) One of the authors (NLT) had the possibility to test featuring the worlds first and only gem quality gemstones in Mogok for GRS over a period of several johachidolite of 14.02 ct. The authors conclude that years, which lead to the discovery of faceted the gem is probably natural, with a possible source in johachidolite and eventually