G&G: Tanzanite, other gems set with colored glue

A colored adhesive is present on the crown facets of this 1.87-carat tanzanite, shown here magnified 20 times. Photomicrograph by Nathan Renfro, (c) Gemological Institute of America (GIA). Reprinted by permission.

We publish courtesy of GIA‘s G&G

Carlsbad, Calif—The latest edition of G&G’s eBriefcontains several items of interest to those on the lookout for colored gemstone treatments: One is the discovery of tanzanite and other gems set with colored adhesive to darken their color, and another is the revelation that a ruby set in a piece of antique jewelry was actually filled with lead glass, a relatively new treatment.

The news was included in a G&G eBrief newsletter sent out Aug. 3 by Gems & Gemology, a Gemological Institute of America publication devoted to the latest gemological research.

The adhesive-set stones were discovered by a California goldsmith who was removing stones from some bezel-set rings that he had purchased in 2009 from a customer who had bought the rings from a TV home shopping network. He noticed that the tanzanite and other gems were set with what appeared to be colored adhesive, and alerted the GIA in March 2010.

Upon inspecting a 1.87-carat tanzanite submitted by the goldsmith, the GIA laboratory team found that a purple-colored flexible adhesive was visible on some of the crown facets, particularly at the corners. After it was removed, the color of the tanzanite appeared “very slightly lighter,” the eBrief said. The goldsmith told GIA that the other stones he removed from the rings became noticeably lighter once the adhesive was removed and that was particularly true for the amethyst.

“The colored adhesive was obviously intended to enhance the appearance of the stones, as well as help hold them in their mountings,” says the G & G eBrief item from GIA. “Buyer beware!”

The second colored stone treatment related item stemmed from a report from the American Gemological Laboratories (AGL), which uses the term “composite ruby” to distinguish lead glass-filled rubies from rubies that undergo the more common heat treatment. The former have drawn a lot of attention within the gemstone trade because they require special care during repairs and can also be damaged by common household chemicals.

The AGL item noted that despite the prevalence of the composite rubies in the marketplace, the lab was surprised to find such a ruby in an antique pendant submitted for identification. The pendant, which did not appear to be a replica, was set with old-mine-cut diamonds and seed pearls, consistent with its apparent age, but the lab identified the center stone as a composite ruby, with an estimated weight of 7.5 carats. The composite ruby had been carefully reset (the milgrain around the bezel was in good condition), and the lab detected no degradation of the glass in the stone—something that could be caused by the jeweler’s torch.

“The fact that this material has started to show up in antique jewelry is representative of how far it has penetrated the market and reinforces the importance of proper identification and disclosure,” the author of the eBrief item, from a staffer at the AGL laboratory, wrote.

India’s polished diamonds exports leap

We publish courtesy of Mineweb

Rising consumer interest from the United States has ensured that the country’s net polished exports rose 74% to $4.18 billion for the first half of the calendar year.

Author: Shivom Seth

MUMBAI – India has emerged as a strong contender in the global gems and jewellery market despite theworld-wide recession and its related setbacks. Demand revival from the traditional markets of the US and Europe is set to spur export growth, ensuring that the value of exports of gems and jewellery expands by around 25% this year.

Demand from the United States, which accounts for more than half of India’s gems and jewellery exports, has been steady and is expected to be rock solid in the coming months, according to traders. Gems and jewellery exports exceeded $28 billion in terms of value in 2009-10, up from $24.4 billion for 2008-09.

Polished diamond exports from the country jumped 79% to $2.2 billion in June 2010, though by volume, polished exports fell 2% year-on-year, as the average price increased 83% year-on-year to $495.01 per carat, according to data provided by the Gems and Jewellery Export Promotion Council. Gold jewellery exports rose to $ 610.4 million in June from $437.24 million of the previous year. The Council has noted that polished imports on the other hand, grew 84% in June 2010, to $1.46 billion, as net polished exports rose 69% year-on-year to $745.6 million.

Gurpreet Chhatwal, director of Crisil Ratings, which has compiled a report on the Indian diamond industry said that though actual consumption has shown an uptrend, restocking by retailers has also ensured a sharp turnaround in demand in the second half of 2009-10. Adding that most retailers maintained minimal inventory during the second half of 2008-09 and the first half of 2009-10, with several jewellers expecting the slump in demand to continue, Chhatwal said the second half of 2009-10 saw a dramatic reversal, with demand increasing significantly.

He added that over the medium term, this would ensure moderate buoyancy in exports by Indian players, despite the prevailing crisis in Europe.

It may be recalled that India’s net diamond account had registered a deficit of $1.19 billion as compared to $148.2 million, a year ago. However, an increase in demand from the US (and partly from Europe) in the month of June 2010, has ensured that gems and jewellery exports jumped 75% to $3.08 billion. Exports stood at $1.76 billion in the same month of the previous year, according to data from the Gems and Jewellery Export Promotion Council (GJEPC), a Mumbai-based organisation.

“There is good demand from the US market and we have noticed a significant upsurge even last month,” said chairman of GJEPC, Vasant Mehta.  “Orders are also picking up in markets like China and Singapore where we have aggressively started marketing our diamonds,” he added.

Among the segments that registered maximum growth were cut and polished diamonds, which grew 78%, followed by gold jewellery that jumped 39% and coloured gemstones that saw an increase of 21%.

The sector, which took a drubbing due to the global economic crisis in September 2008, has seen a reversal in its fortunes, with a slight upsurge witnessed since November 2009. The UAE continues to be the main destination for Indian gems and jewellery, accounting for 31% of total exports, followed by Hong Kong and the US.

Naomi Campbell’s ‘Dirty’ Diamonds Found, Court Testimony Disputed

We publish courtesy of Idex online

In another day of high media attention testimonies, actress Mia Farrow told a court that model Naomi Campbell knew the diamonds she received in 1997 were from the former president of Liberia Charles Taylor.

Farrow is the one that told the press that Campbell received diamonds from Taylor. Taylor is standing trial on 11 counts of war crimes in Sierra Leone.

Last Thursday, Campbell testified that following a gala dinner, during which she was seated next to Taylor, two men gave her a pouch containing “dirty looking stones,” adding that she did not know if Taylor was the one who sent her the diamonds.

In her testimony today (Monday) at the UN war crimes tribunal, Farrow said that Campbell joined her at breakfast, saying in excitement that she received a “huge diamond” from men sent by Charles Taylor.

Meanwhile, the diamonds that were given to Campbell surfaced in South Africa. The British model said in her testimony that she gave the diamonds to an organizer of a South African children’s charity.

Jeremy Ractliffe, who ran Nelson Mandela’s charity, turned over the diamonds to police Friday, a day after Campbell’s testimony. Only licensed diamond traders are allowed to hold on to rough diamonds in South Africa. Ractliffe may therefore find himself in court following a police investigation.

Serene Blush of Morganite

We publish courtesy of Color-n-Ice

In another century far away on the island nation of Madagascar, the delicately tinted pink beryl was first discovered. Beryl is produced in a bouquet of fanciful hues but this ethereal tint warranted a special name.

George Frederick Kunz, called the father of modern gemology bequeathed this charmer with the moniker of Morganite–in a nod to his friend, American financier John Pierpont Morgan, himself a world classmineral collector.

Comparatively rare, this beryl variety appears in a range of pink to rose shades, sometimes with a bit of a brownish peach back color as seen in this magnificent Christian Dior Morganite, pink sapphire and diamond ring auctioned through Christies Hong Kong in 2009. Pre-auction estimates for this beauty ranged between $10,000 to $15,000US but the savvy bidders said more. Gavel came down on almost $68,000 US.

De Beers considering offers for Finsch and Namaqualand diamond mines

We publish courtesy of Mineweb

De Beers has announced that it is considering offers for its Finsch diamond mine and its currently-suspended Namaqualand alluvial operation.

Author: Lawrence Williams

LONDON – The world’s top diamond miner, De Beers, is considering the sale of two more of its older properties – Namaqualand Mines and Finsch Mine in the Northern Cape. Expressions of interest in their purchase has come from third parties on the back of the continuing recovery in the diamond market.

To assess these expressions of interest appropriately, De Beers says it will undertake a systematic review process that will include evaluating the offers received from companies with good mining track records, and strong empowerment credentials. In addition interested parties will have to satisfy many other economic, social and environmental criteria when formulating their submissions.

The Acting CEO of De Beers Consolidated Mines (DBCM), Barend Petersen stated; “We have had approaches from companies interested in discussing the future of Namaqualand Mines and Finsch Mine in the Northern Cape. De Beers has decided to invite separate expressions of interest in each mine through a select tender process.”

De Beers has disposed of several significant older or inactive operations in the past few years – perhaps the most famous of which is the Cullinan (Premier) diamond mine which was sold to a consortium led by Petra Diamonds in 2007.  The Cullinan mine was so renamed in 2003 to celebrate its centenary and was, of course the source of one of the world’s most famous diamonds, the largest rough gem-quality diamond ever found, at 3,106.75 carats and from which two cut diamonds, the Cullinan 1 and Cullinan 2 are some of the biggest attractions in the U.K.’s Crown Jewels.

While De Beers has not said which companies have approached it, the favourite guess is probably Petra which has bought five former De Beers diamond mines in past few years, including the Cullinan noted above, Koffiefontein, the underground operations at Kimberley – all in South Africa and the big Williamson diamond mine in Tanzania.  Another mid-tier diamond miner, Gem Diamonds, with operations in Lesotho (Letseng la Terai), Australia (Ellendale), Indonesia (Cempaka) and with a developing project at Gope in Botswana as well as diamond exploration elsewhere, may also be another possible suitor.

It is expected that the process will take a number of months to reach a conclusion – extending at least well into 2011.  Production at Finsch will continue as planned, while economic development and environmental rehabilitation projects will continue at Namaqualand Mines where production was temporarily suspended in April 2010.

Barend Petersen concluded: “Should  attractive offers be forthcoming the introduction of a new investor at Finsch, with its significant underground resources, and at Namaqualand, with its alluvial reserves, will impact positively on the Northern Cape and extend the life of the mines into the next decade at least. “

Angola Diamond Mine Inaugurated

We publish courtesy of IDEX Online

IGE Resources AB Inauguration its Luxinge diamond mine in Angola. The production at the mine is currently being optimized, the company said, however the mine holds an estimated 1.1 million carats, worth $80-$110 per carat. The Swedish miner, which holds a number of other diamond assets as well as gold and nickel claims, plans to sell this month 8,000 carats of rough diamonds recovered during exploration. Angola’s Minister of Mines Geology and Industry, Joaquim David, the Governor of the Lunda Norte province and the Chairman of Angola’s state owned diamond company Endiama were present at the inauguration, underpinning the importance of the Luxinge project to the Angolan diamond industry. IGE is the largest shareholder of the Luxinge diamond company with a 42 percent interest. The company’s Cassanguidi mine has been producing diamonds “for some months already,” according to IGE CEO Tomas Fellbom.