Largest Blue HPHT Synthetic Diamond in GIA Lab

A 5.03 ct Fancy Deep blue HPHT synthetic diamond was examined by GIA (left). Faint but sharp color zoning was observed (middle, field of view 4.77 mm) along with small metallic inclusions and a cavity at the girdle (right, field of view 2.19 mm). Photos by Sood (Oil) Judy Chia (left) and Kyaw Soe Moe (center and right)

A 5.03 ct Fancy Deep blue HPHT synthetic diamond was examined by GIA (left). Faint but sharp color zoning was observed (middle, field of view 4.77 mm) along with small metallic inclusions and a cavity at the girdle (right, field of view 2.19 mm). Photos by Sood (Oil) Judy Chia (left) and Kyaw Soe Moe (center and right)

The largest faceted colorless HPHT-grown synthetic diamond reported to date is a 10.02 ct E-color, VS1-clarity specimen, cut from a 32.26-carat piece of rough, was reported by IGI Hong Kong in 2015. The diamond was grown by NDT, or New Diamond Technology, is one of the founding members of the new International Grown Diamond Association. Recently, large colorless and near-colorless HPHT-grown diamonds by the Russian company have been investigated by GIA laboratories. The sizes ranged up to up to 5.11 ct. In January 2016, GIA’s New York laboratory examined a 5.03 ct fancy-color HPHT-grown type IIb synthetic diamond produced by NDT. this is the largest faceted blue laboratory-grown diamond studied so far. 

The notes from GIA's lab report stated that the 5.03-carat diamond exhibited a number of traits characteristic of diamonds grown using the high-pressure, high-temperature (HPHT) process, including color zoning and a cuboctahedral growth pattern. The stone was graded a VS1, fancy deep blue. 

"This emerald-cut synthetic diamond was color graded as Fancy Deep blue. This is a very attractive color with no other color component, a prized rarity among natural type IIb diamonds (the Blue Moon, for instance, was graded as Fancy Vivid blue). When viewed under a microscope, faint but sharp color zoning could be seen, indicative of the uneven impurity incorporation of HPHT synthetic diamonds. No strain was observed under crossed polarizers, indicating a very low dislocation density, which is also characteristic of HPHT-grown diamonds. It had VS1 clarity, with only very small metallic inclusions and a cavity observed at the girdle. Fluorescence and phosphorescence images collected using a DiamondView instrument revealed the sample’s cuboctahedral growth pattern, another feature of HPHT synthetics. The long-lasting chalky blue phosphorescence was further analyzed using spectroscopy, and the emission was found to originate from two broad bands centered at approximately 500 and 575 nm (figure 2, right). These bands have previously been reported in NDT’s type IIa and IIb HPHT synthetic diamonds (D’Haenens-Johansson et al., 2015). "

The evaluation of a lab-grown blue diamond of this size is considered by the researchers to be so significant that they opted to publish Lab Notes online ahead of the next quarterly edition of Gems & Gemology.  

To read Lab Notes GIA.edu

'Sunrise Ruby' Steals the Show at Sotheby's Auction

sunrise

The “Sunrise Ruby,” a 25.59-carat untreated pigeon’s blood red-colored stone set a new world auction record for price paid for a ruby on Tuesday at the Sotheby's Geneva sale. The ruby was initially estimated to sell at between $12-$18 million but bidding soared to $30.3 million, demolishing the existing ruby auction record that was held by the $8.6 million sale of the “Graff Ruby.” The ring also set a record for the price paid for a jewel by Cartier. It was sold to an million to an anonymous buyer.
The high price of the ruby heavily contributed to the Sotheby’s Magnificent and Noble Jewels auction which the highest-ever total for any jewelry auction at $160.9 million, deposing the Christie’s November 2014 sale of Magnificent Jewels in Geneva, which totaled $150.2 million.

Also performing well but not meeting pre-sale expectations was the “Historic Pink." The 8.72-carat fancy vivid pink diamond sold for $15.9 million, below its pre-sale high estimate of $18 million.
David Bennett, worldwide chairman of Sotheby’s international jewelry division had this to say about the sale: 
“(The) record result is the reflection of outstanding quality of the pieces in the sale across the board,...The galleries have been brimming with collectors during our worldwide exhibitions, and this translated into lively bidding throughout the sale … with truly global demand for the finest diamonds, gemstones and signed pieces of the very highest order.”

The entirety of the auction results can be viewed at Sotheby's 

Sotheby's to Auction a Historic Pink Diamond

Historic pink

A fancy vivid pink diamond that is believed to have been part of the collection of Napoleon Bonaparte’s niece, Princess Mathilde, could fetch up to $18 million when it hits Sotheby’s auction block next month.
Dubbed the “Historic Pink Diamond,” the diamond is an 8.72-carat stone, VS2 clarity and is a non-modified cushion cut; unusual for a pink diamond.

Scheduled for May 12 Sotheby’s auction of Magnificent Jewels and Noble Jewels, in Geneva.

Kathleen Marino M.A, G.G., AJP, NAJA

Exceptional 63.05-carat Diamond Found

Lucapa Diamond Company recovered an “exceptional” 63.05-carat, Type IIa diamond from its alluvial mining operations at the Lulo Diamond Concession in Angola. It is the biggest diamond recovered since Lucapa started commercial mining operations at the site in January and the company’s third-largest stone unearthed at Lulo, behind 131.40-carat and 95.45-carat stones (both of which also were Type IIa).

Kathleen Marino M.A, G.G., AJP, NAJA

Angola diamond

The “Kimberley Purple"

kimberlypurple

The “Kimberley Purple,” a 30.80-carat rough diamond found in Batla Minerals’ Superkolong diamond tailings plant in Kimberley, South Africa, is on view in New York until April 23, when it will be moved to Antwerp for tender. 
A viewing can be arranged by emailing appts@fusionalternatives.com. Additional information on the tender can be found on the Fusion Alternatives website. 

Kathleen Marino M.A, G.G., AJP, NAJA

AGTA Spectrum Awards 2015

The 2015 AGTA Spectrum award winners were announced. The categories cover everything from objects of art, faceted stones, carved stones, and jewelry for every occasion you can think of. 
Here is just a taste of the entries that I thought were truly spectacular. 

1st Place Cut Stones: Phenomenal category, Robert Shapiro Madison, WI
Natural split pair of boulder Opals (60.50 ctw.).

Editors' Choice: Evening Wear Gregore Joailliers Santa Barbara, CA
18K white gold "Sometime This Spring"
earrings featuring Mexican fire Opals (68.88 ctw.) accented with round Diamonds (2.19 ctw.).

Honorable Mention: Men's Wear William Travis Jewelry Chapel Hill, NC
18K yellow gold and sterling silver ring featuring a 13.17 ct. Citrine.

    
1st Place Carving Naomi Sarna Designs New York, NY
"Rose de France" Amethyst carving (1015 ctw.).

    
2nd Place Evening Wear Erica Courtney, Inc.  Los Angeles, CA
18K yellow gold "Milky Way" earrings featuring Opal drops
(46.06 ctw.) accented with Diamonds (1.98 ctw.) and Paraiba Tourmalines (2.03 ctw.).