Gemmology: 6 precious stones that have hit the market recently

Selina Denman rounds up some of the most important precious stones – loose and mounted – that have come to the market in recent times.

La Gloria

At a whopping 887 carats, La Gloria is one of the largest rough emeralds in the world, overtaking the 857-carat Gachalá displayed in the ­Smithsonian ­Institution in Washington. The stone's blue-green hues and small surface calcite matrix lend ­evidence to its museum-quality provenance. La Gloria comes from Colombia's Muzo mine, producer of some of the ­largest and finest emerald crystals in South ­America. La Gloria is part of the acclaimed ­Marcial de ­Gomar Collection, part of which is ­being ­auctioned off by New York-based Guernsey's on April 25. Also ­included in the rare-emeralds ­auction are 20 loose stones (cut and rough) and 13 pieces of jewellery. These include the Marcial de ­Gomar Star, perhaps the first-ever double-sided star ­emerald; and the Tears of Fura, a pair of ­matching teardrop-shaped gems. The auction is also going to display the ­largest assemblage of cut emeralds recovered from the wreckage of the Spanish ship Nuestra ­Señora de ­Atocha, which sank in 1622 off the ­Florida Keys. ­Manuel Marcial de Gomar is the founder of ­Emeralds International, which offers top-quality rough and cut emeralds from Colombia, Brazil, Zambia, ­Zimbabwe, ­Madagascar and Afghanistan – both loose and incorporated into de Gomar's ­designer settings.

Eyes of the Dragon

Part-owner by Gemfields, the Montepuez Ruby Mine (MRM) in Mozambique is one of the most ­significant ruby deposits to have been ­discovered in recent times, and offers up rubies that are up to 500 million years old. One of the most ­significant finds so far is a matching pair of rough rubies with a ­combined weight of 45 carats. The gems were ­acquired by Veerasak Gems of Thailand and ­subsequently named the Eyes of the Dragon. “Looking at them makes me tremble,” said one of Veerasak’s ­founders. After the successful sale of these ­matching rubies, and in keeping with its ­commitment to ethical ­mining ­practices that ­support local communities, MRM made a ­commitment to support the Niassa Lion Project in the Niassa ­Reserve in northern ­Mozambique, an area of profound importance for the global conservation of African wildlife, ­particularly lions, wild dogs and elephants.

Peacock Pearl

The Robert Wan group has spent more than 40 years developing and harvesting Tahitian pearls. Today, the brand’s pearls are recognised for their quality and lustre, and the range of colours on ­offer, which include blue-green peacock hues, and shades of grey and cherry. “Peacock, our rarest colour, is a symbol of protection and guidance, as believed by native ­Tahitian people,” Wan notes. But Wan’s ­creations are perhaps most remarkable for their size, which is often 13 millimetres and above. The peacock pearl pictured here, for example, ­measures 17mm and took a decade to harvest. “As nature is very ­unpredictable, this pearl owes its rarity to its smooth surface, its magnificent peacock colour and its ­perfect round shape,” Wan explains. “Round pearls represent a maximum of three per cent of the ­total harvest. It was kept in my personal ­collection for ­several years, waiting for the perfect creation that will ­embrace its value.” The opportunity ­finally arose in the form of the Enso necklace, which was unveiled at the Doha Jewellery & Watches ­exhibition this year. ­Inspired by Japanese ­calligraphy and priced at US$3.5 ­million (Dh12.85m), Enso was ­created in ­collaboration with French designer ­Arnaud ­Flambeau. The three-strand necklace ­consists of 23 meticulously matched, cascading Tahitian peacock pearls, as well as 101 ­carats of brilliant diamonds, with this 17mm ­peacock pearl, paired with a 10-carat diamond, ­sitting at its centre. Notably, all of the ­diamonds were cut and polished in Dubai.

The Pink Star

Described as “a true masterpiece of nature, beyond characterisation with human vocabulary” by the Gemological Institute of America (GIA), The Pink Star diamond was auctioned off for record US$71.2 ­million (Dh261 million) on April 4, as part of the Sotheby’s Magnificent Jewels sale in Hong Kong. The 59.60-carat, oval, mixed-cut pink diamond is the largest internally flawless fancy vivid pink diamond that the GIA has ever graded – and is more than twice the size of the Graff Pink, a 24.78-carat fancy intense pink diamond that formerly held the world auction record for any pink diamond. The Pink Star was mined by De Beers in Africa in 1999, and in its rough state weighed 132.5 carats. It was meticulously cut and polished over a period of two years, and made an impromptu two-day visit to Dubai last month, where it was showcased in the new Sotheby’s gallery and office space in Dubai International Financial Centre. “This is an extraordinary stone, on every level,” says David Bennett, worldwide chairman of Sotheby’s jewellery division, when we meet him in Dubai. “Pink is, for most people, the most attractive colour of diamond, and this is the biggest and it is flawless. If you have one that’s 10 carats, that’s amazing; to have 60 carats is just phenomenal. We thought we’d bring it to Dubai because it’s something that most people will have never seen and will probably never see again.”

The Stotesbury Emerald

This gem has been in the possession of some of ­history’s most avid jewellery collectors, and will be looking for a new owner when it goes on sale on April 25 at the Sotheby’s Magnificent Jewels ­auction in New York. Weighing about 34.40 carats, the Stotesbury Emerald is expected to fetch ­between US$800,000 and $1.2 million (up to Dh4.4m). The hexagonal-shaped, classic Colombian emerald has been owned by three very different women, who wore the stone in three different ways. The ­initial owner was American mining heiress Evelyn Walsh McLean, the ill-fated owner of the Hope diamond. She ­enlisted Pierre Cartier to have the emerald mounted as a pendant. The second owner was Eva Stotesbury, second wife of the prominent ­American investment banker ­Edward Stotesbury, who had the gem ­incorporated into a suite of ­emerald ­jewellery. This was subsequently acquired by ­Harry ­Winston, who is responsible for the emerald’s ­current ­iteration: as an oversized ring encircled by ­diamonds. May Bonfils Stanton bought the ring from Harry ­Winston and sold it in a ­Sotheby’s sale in 1971. The gem’s whereabouts were a mystery from 1971, and it has only recently resurfaced.

Mountain Star Rubies

Star rubies have fired the imaginations of ­collectors for centuries – for their resplendence and ­rarity alike. As the name suggests, these are gems that contain needle-like rutile fibres under their ­surface, with six, evenly proportioned rays ­being the most desirable. When fishing guide Jarvis Wayne ­Messer, from North Carolina, stumbled upon a haul of four star rubies in 1990, experts labelled it the ­finest ­collection in the world, all the more ­astounding for its North American origins, so far away from the stone’s usual haunts in Sri Lanka and ­Myanmar. The Mountain Star Ruby collection collectively weighs in at 342 carats and includes: the 139.43-­carat ­Appalachian Star (pictured, left); the 64.16-carat Promise Star; the 52.36-carat Misty Star; and the 86.56-carat Smokey Mountain Two Star Ruby ­(pictured, right), which features stars on both the front and back of the stone. The Mountain Star Ruby Collection will be sold together as one lot through Guernsey’s auction house, with a date for the sale due to be announced imminently.