| Hong Kong Jewellery 香港珠寶
Search
業內要聞及精選文章

News

  1. Pandora Unveils First Ever Art Collaboration - Keith Haring X Pandora
  2. Further Growth in Hong Kong’s Luxury Retail Sales
  3. Pandora Unveils First Ever Art Collaboration - Keith Haring X Pandora
  4. Further Growth in Hong Kong’s Luxury Retail Sales
  5. Platinum Jewellery Sales Rise in Key Markets in Q2 2022, PGI says
  6. AGTA Announces New Board Members
  7. Fura Gems Discovers 101-carat Ruby
  8. Lightbox Sells Lower-Quality Lab-Grown Diamonds
  9. 160-Carat Rough Unearthed from Angola Mine
  10. GIA Found Synthetics, Simulant among Four ‘Natural’ Sapphires
  11. ‘De Beers Blue' Might Originate from Deep Earth, Says GIA
  12. New Chairman Elected at India’s GJEPC
  13. Tiffany Launches Its First All Gender Bangle Collection
  14. Pandora Launches Lab-grown Diamond Jewellery Collection in North America
  15. Gemfields Reports Record Revenues
  16. IIJS Premiere Sees Record Number Visitors
  17. Signet Acquires Blue Nile for $360M
  18. Hong Kong jewellery sales slide in H1
  19. Fancy Colour Diamond Price Index Rises
  20. The Potentially Largest Pink Diamond Found in 300 Years
  21. Kering Reports Strong First Half Jewellery Sale
  22. Vicenzaoro Back In September
  23. eBay Offers Fine Jewellery Authentication with GIA Partnership
  24. New Executive Director and Secretary General Appointed for Watch & Jewellery Initiative 2030
  25. VO Vintage Returns To Vicenzaoro September
  26. Sarine Partners With NGTC on Grading Reports In China
  27. Diamond Prices Slide Amid Economic Uncertainty
  28. De Beers, Botswana Sales Agreement Extended
  29. AWDC Appoints David Gotlib As New President
  30. IGI Debuts Online Learning Courses
  31. Swarovski Appoints First Non-Family CEO
  32. Kashmir Sapphire Ring Comes Out on Top at Bonhams
  33. WJA Foundation Launches New Scholarship for Women of Colour
  34. Blue Nile Merges with Mudrick for Its Second IPO
  35. RJC Launches ‘Gender Equality Toolkit’ at JCK Las Vegas
  36. GIA Reports to Go Digital by 2025
  37. Gemfields Achieved Highest Revenue at Emerald Auction
  38. DAMAC Group Now Owns de GRISOGONO
  39. GJEPC Proposes Lab-Grown Diamond Park in India
  40. Pandora’s New Crafting Facility in Vietnam Costs $100M
  41. Q1 Gold Jewellery Demand Soft, Says WGC
  42. Jewellery Buying Groups Formed New Global Alliance
  43. Singapore to Host Jewellery & Gem World 2022
  44. ‘Wonder Woman’ Gal Gadot Premiered in Tiffany’s 2022 High Jewellery Collection
  45. Christie’s to Auction ‘The Light of Africa’ for $18M in June
  46. New Board of Directors were elected to Jewellery Exporters Association of Turkey
  47. Oroarezzo back with Première Competition
  48. ‘De Beers Blue’ auctions US$57.5M at Sotheby’s
  49. CTF launches Mother’s Day collection
  50. Jewelers of America Announces The 2022 CASE Award Winners
  51. De Beers: Diamond Businesses Staying Cautious About Business Expectations
  52. Synthetic Alexandrite Pioneer David Patterson Dies at 89
  53. 205 CARAT FANCY INTENSE YELLOW DIAMOND GENEVA MAGNIFICENT JEWELS | 11 MAY 2022
  54. Rebecca Foerster Appointed As President of Hearts On Fire
  55. US Steps Up Sanctions Against Alrosa
  56. PGI Study Findings: Consumers Have Different Interpretations of Sustainability
  57. Irving Wong Appointed as Pandora’s General Manager For China
  58. Rolex’s 6 New Watches Unveiled at Watches & Wonders Geneva
  59. Sixième Sens par Cartier High Jewellery: Heteractis Ring
  60. Will Russian Diamond Ban Help Foster Lab-Grown Diamond Business?
  61. Press Release: Ariana DeBose, Hunter Schafer and Zoey Deutch Shine in De Beers Jewellers at the Vani
  62. Press Release: Ariana DeBose, Hunter Schafer and Zoey Deutch Shine in De Beers Jewellers at the Vani
  63. JEWELLERY GENEVA Takes Place between 30 March and 3 April 2022
  64. Christie’s Presents 228 carat White Dimond
  65. Gold Bar Integrity Programme to be Implemented
  66. Press Release: BONHAMS ANNOUNCES ACQUISITION OF BRUUN RASMUSSEN AUCTIONEERS – DENMARK’S LEADING AUCT
  67. Early Spring Fashion for Natural Diamonds
  68. Jennifer Garner Shines in De Beers Jewellers at the Premiere in New York
  69. To celebrate its 15th anniversary, “Cartier Women’s Initiative Impact Report”
  70. American Gem Trade Association Announces Partnership with JCK Show Again
  71. Chow Tai Fook and Canada's Mountain Province Diamonds Sign Supply Agreement
  72. Registration Is Open for 2022 JCK Show
  73. Alrosa Caught Up in U.S. Sanctions
  74. Tawhid Abdullah Receives Lifetime Achievement Award
  75. The Largest Blue Diamond Appears at Sotheby’s Auction
  76. Price Rise for Nearly 90% Of Fancy Colour Last Year
  77. Dickson Yewn’s Collectibles Given for Sotheby’s Charity Auction
  78. De Beers Boosts Production
  79. Watches & Wonders Geneva To Be Held In Hybrid Format
  80. Jewellery, Gem & Technology Dubai to Debut February
  81. Hong Kong Losing its Dominance as the World's Largest Watch Market
  82. Gift Guide for CNY
  83. Press Release: Sotheby’s Announces New Appointments To Luxury Team In ASsia
  84. Georg Jensen Becomes a Certified Member of RJC
  85. 555.55-carat Black Dimond Unveiled at Sotheby’s Auction
  86. GIA Appoints Anna Martin as SVP for Institute, Industry Relations
  87. Alrosa Boosts Direct Sales of Fancy Diamonds to Investors
  88. CIBJO General Assembly postponed to March 17 and 18, 2022
  89. 7,525 Carat Emerald Discovered
  90. Karl Lagerfeld Jewellery Collections to Shine
  91. Diamonds Travel To The Space
  92. Vicenzaoro January postponed to March
  93. America’s Youngest Jeweller Starts Business via Instagram
  94. Concerns over conflict gold arise again
  95. The 1st International Gemstone & Diamond Trade Summit Wraps Up in Macao
  96. The Knot’s Study:Over 30% of Respondents Say Natural Diamond Unimportant
  97. Pantone’s 2022 Colour of the Year: Very Peri
  98. Phillips Jewellery Auctions Fetch over HK$181 Million
  99. The World’s First Pure Gold Castle of Magical Dreams by CHOW TAI FOOK
  100. Jewellery Sales Jumped 78% During the Thanksgiving Holiday
  101. Gem Auctions DMCC’s Debut Auction Successful
  102. Cartier’s Christmas Tree Lights Up the City with Love and Hope
  103. Rediscovering Lacloche in Hong Kong
  104. Blue diamonds to lead Christie’s HK autumn sale
  105. JMA show to stage next Thursday
  106. HK auction to help Cambodian kids
  107. Basel fair cancelled again
  108. HKDI show to continue in Dec
  109. Gemfields sells 7,500-carat emerald for good
  110. Sustainability is key to diamond purchases, a report says
  111. Christie’s Geneva jewellery sale fetches CHF53.7m
  112. Cibjo forms working group on fei cui standards
  113. Only Watch raises CHF30m for DMD research
瀏覽更多...


HIGHLIGHT

  1. US market unfolds changes and potential
  2. The queen of gems, the gem of queens
  3. Classics return

Advertisement

  • River panning
  • Peridot roughs
  • Ruby roughs
  • an opencast mining site
  • After heating, the gemstone is being cooled down.
  • Drill a hole deep down to the ground for gemstone excavation
  • An insect inside amber
  • Ruby roughs
  • A cave mining site
  • Jade market in Mandalay
  • A typical gemstone market in Mogok

Mogok mines study mission

 

Mogok, Myanmar, is praised as the ‘gemstone capital’ for producing top-quality ruby. The author paid a visit to gemstone mines in the region late last year to gain a first-hand account of the mining activities of ruby and other coloured gemstones.

 

Joanne Chan

 

In mid-December 2015, Dr Edward Liu led a Hong Kong study mission to Mogok to understand the current state of the local gemstone mining practice and the environment. The 18-member group includes jewellery trade practitioners, gemmologists as well as gemstone and mineral lovers from other industries. I set off on 18 December with great excitement. By midnight we arrived in Bangkok, Thailand and stayed at a hotel nearby to catch the flight next day to Mandalay, Myanmar.

 

Upon arrival in Mandalay, we exchanged the local currency and applied for visas to enter Mogok. In the afternoon we stopped by a local jade market that sold mostly fei cui of unequal qualities. Medium- and low-priced green fei cui cabochons were a common scene.

 

On the next day, we rode on a 4WD for six hours before reaching the Mogok mining area. We took the old route; the highway is narrow and built along the rugged mountain terrain. The Mogok mines are located in the province of Mandalay, about 200km to the northeast of the city. Since the military government took control of Myanmar in the 60s, the area had adopted a closed-door policy that prohibited foreigners’ entry. The area only reopened in 2012 but visitors must be led by a local tourist guide permit holder and apply for a visa to access the Mogok mines. After passing the visa inspection point in the area, we entered the mines. The six-hour journey was bumpy and exhausting. In the end we were met by a sign reading ‘Welcome to Ruby Land’. We finally reached the mysterious Mogok.

 

Mid-December does not fall into the rainy season in Mogok. It is therefore suitable for mine visit. There was considerable temperature difference between day and night. While the temperature was seven degree Celsius in the morning and at night, it could be as high as 20‮"‬J in the afternoon. Sunrise time was about 6:30AM when the fog was dense. As temperature rose during the day, the fog dissipated and a blue sky was revealed.

 

Some of the mines in Mogok are operated by the government while some others are co-operated by the government and private enterprises. The geological features of Mogok are complex, with different mines having their own characteristics and rock types which can be divided into primary and secondary deposits. Rocks of primary deposits are mainly composed of metamorphic gneiss containing scapolite and garnet; granite containing pyroxene, amphibole and feldspar; pegmatite containing gemstones such as rock crystal, topaz, tourmaline and beryl; ultrabasic rocks containing peridot; metamorphic marble containing ruby and spinel, etc. Secondary deposits are layers of gravel that are mostly found in deep valley and the two sides of mountains. Commonly found gemstones include ruby, spinel, rock crystal, tourmaline, feldspar, etc.

 

During our five-day stay in Mogok, we have visited a number of mining areas including the Lin Yaung Chi mine and the Shwe Pyi Aye mine in the east. The two primary deposits of corundum were first mined in 1975 and 1995 respectively. The Pyaung Guang Village in the north is a primary deposit of peridot. The Chaung Gyi mine in the northeast is a primary and secondary deposit of spinel and sapphire. In the west there are Ruby Primary mine, Kadoketart mine and Thet Naing Aung mine, which are all primary deposits of ruby. The Kyautpyattat mine and the Baw Lone Gyi Htay Paing mine are primary deposits of ruby and spinel. The Sakangyi mine is a primary pegmatite deposit of topaz, crystal and aquamarine.

 

Since each mine has its own characteristics, different mining methods are therefore employed.

 

•Kadoketart mine: Miners drill holes down to the earth and excavate gemstones with simple tools of cables and pulleys.

•Ruby Primary mine and Baw Lone Gyi Htay Paing mine: Miners make tunnels parallel to the ground on the side of the mountain, and transport mineral rocks to the ground with trolleys.

•Lin Yaung Chi mine: An opencast mining method; miners blast the rock with explosives and then wash the gravel with powerful jets of water to collect gemstones.

•Kadoketart mine and Kyautpyattat mine: A cave mining method; miners climb into the caves according to their formation. This mining method is very dangerous but could best preserve the appearance of the rough gemstone.

•Alluvial mining is commonly adopted in secondary deposits by combining the flow of the stream and the old sieving method.

 

Currently, the Myanmar government has imposed environmental regulations on the mining industry. Environmental protection work such as tree plantation must be carried out after the mine is closed in order to restore the land. Besides, mining waste will be passed to the women in the villages, who could own the gemstones obtained from sieving.

 

Various coloured gemstones are produced in Mogok. Their respective properties are listed below:

•Ruby: Production from primary deposits including the Kadoketart mine and the Thet Naing Aung mine are of the best quality.

•Sapphire: Good clarity and beautiful colours. Many special sapphires are also produced, including star sapphire, trapiche sapphire and a paragenetic gemstone of sapphire and spinel.

•Spinel: Formed in metamorphic marble with beautiful colours and perfect crystal structure

•Peridot: The crystal structure is flatter and more elongated compared to peridot produced in other countries. The most common colour is yellowish green.

•Tourmaline: With radiating crystals resembling grapes and triangular coloured growth zones on crystal structure. 

•Amber: With inclusions such as mosquitoes, small worms, ants and plants

•Painite: Only found in Myanmar so far

•Hackmanite: a type of sodalite which is in purple or pink

 

Apart from the above gemstones, apatite, diopside, fluorite, kornerupine, moonstone, rock crystal, scapolite, topaz and zircon can also be found in Mogok.

 

Besides visiting mines, we also had a chance to witness the heat treatment process of spinel. Very traditional practices were adopted: the sample was put inside a bottle sealed with clay. It was heated in the furnace to 1,200‮"‬J. After 20 minutes of heating, it was cooled down for 10 minutes. The gemstone was then soaked in red oil for several seconds and the entire treatment is done.

 

As for heat treatment of ruby, it requires a temperature of 1,800‮"‬J, ten to 15 minutes of heating, twenty minutes of cooling and soaking in red oil for several seconds.

 

In Mogok, the gemstone marketplace is rather primitive. As far as we saw, transactions were carried out at tea stalls or in open areas with parasols, tables and chairs where sat some buyers who were waiting for suppliers. Most merchandise is rough or cut gemstones of lower grades. Sellers often charge very high prices as much as 10 to 20 times of the market prices. It takes time to bargain. Only patient and experienced buyers are able to make a good deal.

 

The short mission has significantly enriched our knowledge. Despite the tough journey, it is a precious opportunity to understand the environment of the main mining areas of Mogok and the characteristics and mining methods of different mines, not to mention to take a closer look at gemstone heat treatment. I would like to take this opportunity to thank Dr Edward Liu for his nice arrangement.

 

Joanne Chan is the chief gemmologist of the Hong Kong Jade & Stone Laboratory Ltd.   

 

← Back