Latest GRS News


NDT Breaking The 10 Carat Barrier – World Record Synthetic Diamonds Investigated

Introduction The first small manufactured industrial diamonds were produced in 1953 by the Swedish company ASEA but their accomplishment went unannounced. In 1970, General Electric (GE) produced synthetic diamond crystals using the HPHT method with a belt type of press and created a 0.78ct polished RBC colorless diamond. In the 1980’s and 1990’s Russians used […]

Discoveries, News

Record Sale of Magnificent Pigeon’s Blood Ruby and Diamond Necklace

A magnificent Burmese Pigeon’s Blood ruby necklace was sold for a total price (including buyers premium) of more than US$ 13 million at the Christie’s Magnificent Jewels auction on 2 June 2015 in Hong Kong. The achieved price makes it the most expensive ruby necklace ever sold at an auction. The outstanding necklace comprises of […]


GRS Alert: New spinel treatment discovered involving heat- and cobalt-diffusion

Introduction Cobalt-spinels are considered one of the most precious spinel and are rarely colored blue with or without grey to black tones. Blue Cobalt spinel are at least 10-100x more expensive per carat than grayish-blue colored spinel. Cobalt intensifies the blue color in spinel, considerably enhancing its beauty. Cobalt-spinel over 5ct can be 10,000 to […]

Alerts, News

The making of an international color standard by GRS: ‘Pigeon’s Blood’ & ‘Royal Blue’

Definitions, Retrospective and Future By Dr. A. Peretti, Director GRS Laboratories DEFINITIONS While pigeon’s blood color description was used in the past in the literature for rubies, GRS first made a master set for rubies that defined what pigeon’s blood is in comparison to the intensity of red, namely vivid red was chosen as the […]


GRS Alert: Warming of Mozambique rubies previously certified as unheated by GRS

We would like to inform our customers that rubies found to be unheated when tested by GRS are sometimes heated after certification and presented as natural unheated rubies to the market without re-certifying with GRS. This very low temperature warming does not require repolishing of the stone and therefore no weight loss and no dimension […]

Alerts, News

GRS Grand Opening Bangkok

On the 29th June 2014 we celebrated the opening of our new laboratory facilities in Bangkok. Thank you very much everyone for coming and celebrating this milestone with us. Here some impressions from the event:


GRS ‘Pigeon’s Blood’ report types for rubies

Burmese Pigeon’s Blood report sample:     Mozambican Pigeon’s Blood report samples: Type A: Ruby from Mozambique with considerable fluorescence is described as previously indicated by the descriptor GRS-type Pigeon’s Blood, owing to a similarity in color with its Burmese counterpart. Type B: Rubies typically appear as vivd red, reminiscent in color saturation of Pigeon […]


GRS Alert: Next-generation of synthetic diamonds reach market

CVD-grown Blue Diamonds – Identified by GRS and CGL-GRS laboratories Hong Kong, Lucerne and Vancouver – A distinctly new type of synthetic blue diamond sized from 0.25 carats to over 1.25 carats turned up at both the Bangkok and Hong Kong Gems & Jewellery Fairs in September 2013 along with pink, yellow, and colourless varieties of […]

Alerts, News

A review of beauty and rarity of Mozambique ruby

by Dr. A. Peretti From today’s perspective, it would be impossible to overstate the significance of African rubies in the gemstone trade. East African ruby, specifically from Mozambique, Tanzania and Madagascar, has recently dominated the market for several reasons; lack of thermal enhancement, brilliancy, size and for its color. No other geographical region has successfully […]


GRS Lab Seminar during September Hong Kong Jewellery & Gem Fair, 16th September 2013

The Mogok Mines – New & Previously Unseen 3D Mining Images and The Origins of Spinel – A 10 Year Research Summary On 16th September 2013, GRS held a seminar about the latest GRS expedition to the Mogok ruby, sapphire and spinel mines (Part I) as well as the world of magnificent spinels – provenance […]