The Hope diamond/Tavernier Blue diamond, another Golconda diamond with a fancy dark grayish-blue color on display at the Smithsonian's National Museum of Natural History.
Given the period of origin of the Marie Antoinette Blue Diamond as mid 18th-Century and the color of the diamond is fancy grayish-blue, the most probable mine of origin of the celebrated diamond, is the Golconda Mines situated on the eastern side of the Deccan in Southern India, in the lower region of the Kistna river basin, and include some of the oldest and most famous of Indian diamond mines, such as the Kollur mines and Parteal mines. Diamonds were first discovered in Kollur around 1560. The main source of blue diamonds in the world in ancient times was the Kollur Mines of Golconda. Famous historic blue diamonds like the Hope diamond, Tereschenko diamond, Wittelsbach-Graff diamond,Sultan of Morocco diamond and the Brunswick Blue diamond, all originated in the Kollur Mines of Golconda. In the mid 18th-Century, when the Marie Antoinette Diamond first appeared, the only source of blue diamonds in the world was the Kollur Mines of Golconda, and hence the most probable source of the Marie Antoinette Diamond was these mines.
Although, the diamonds mines of Brazil were discovered around 1725, and significant quantities of colorless diamonds entered the diamond markets of the world in the mid and late 18th-Century, the discovery of a significant blue diamond has never been reported from Brazil. On the other hand several extremely rare red diamonds have been reported from Brazil, such as the Mousaieff Red, Rob Red diamond etc. According to Rafal Swiecki, geological engineer, 40 per cent of Brazilian diamonds are completely colorless of which 25 per cent are of the purest water and top quality. About 30 per cent show a slight tinge of color, and though the remaining 30 per cent have a pronounced color, stones of a deep and beautiful shade are rare. The colors which have been observed in Brazilian stones are yellow, red, brown, green, gray, and various shades of black; blue is rare, but a few stones showing a beautiful shade of this color are said to have been found.
Being Golconda diamonds the 45.52-carat, antique cushion brilliant-cut, Hope diamond and the 5.46-carat, heart-shaped Marie Antoinette Blue Diamond share almost the same color, fancy grayish-blue color, but the Hope diamond is a little darker in color and described as a fancy dark grayish blue color.
The List of known famous blue diamonds in the world arranged in descending order of carat weights, which includes the Hope diamond, Tereschenko diamond, Wittelsbach-Graff diamond, Sultan of Morocco diamond, the Brunswick Blue diamond, Marie Antoinette Blue diamond etc. can be seen by clicking the link below :-
The last time we heard about the Marie Antoinette Blue Diamond was in 1983, when the celebrated diamond came up for auction at Christie’s, Geneva, but was not sold. Hence, the diamond apparently remains with the same private collector from Europe, who purchased it in 1967, at the Palais Galliera in Paris.
The Marie-Antoinette Blue Diamond, is a 5.64 carat, blue, heart-shaped diamond which the queen had set in a ring.The queen is said to have given the ring to her close friend, the Polish Princess Lobomirska, shortly before her trial in 1791. After the Polish princess died her estate was passed to her four daughters. The diamond became the property of Count Vladimir Potocki through his marriage to one of the daughters. The blue diamond was displayed at a number of prestigious exhibitions throughout the 19th century,
Please upload images of the rough grey diamond and give more details such as the carat weight of the stone, the mine-of-origin, country-of-origin, a description of the rough stone, any document certifying that the grey stone is a diamond etc. that may be helpful in evaluating the price of the stone.
The image of the white rough stone uploaded by Guru is definitely not a diamond. Diamonds are not found in Sri Lanka, even though the country is blessed and has almost 75 varieties of gem minerals out of the nearly 200 recognized gem minerals found around the world. Main varieties of gem minerals found in Sri Lanka are Corundum (blue sapphire, ruby, pink sapphire, yellow sapphire, padparadscha, white sapphire, star sapphire, star ruby, geuda sapphires), Chrysoberyl (yellow to green chrysoberyl, catseye chrysoberyl, alexandrite, cat's eye alexandrite), Beryl (aquamarine), Spinel (the most abundant gem mineral found in Sri Lanka - The range in color of Sri lanka spinels are ruby red, pink, orange, shades of reddish brown, purple, blue, bluish green, mauve, greenish black, black to colourless), Garnet (Alamandine, Pyrope-Rhodolite, Spessartine, Grossular-Hessonite), Tourmaline (common colors found in Sri Lanka - yellowish green, dull green, honey yellow brown and rarely blue and bright green. Most abundant yellowish-brown), Quartz (purple-Amethyst, yellow/orange-Citrine, rose quartz, white quartz, brown quartz), Topaz (white), and Feldspar (Moonstone).
The varieties of white gem minerals found in Sri Lanka are white sapphire, white spinel, white quartz, white topaz, white zircon known as Matara zircon and white moonstone. Hence the white rough stone you have uploaded can be any one of these white gem minerals.
Sapphires have a hexagonal bipyramidal crystal habit as seen in the image of a white sapphire mined in Sri Lanka. However most sapphires mined in Sri Lanka have lost this hexagonal bipyramidal shape due to erosion caused over millions of years. The image of the rough stone you have uploaded (Images 3 and 4) have a pyramidal shape at least on one side of the stone and may be an indication that it is a white sapphire.
All varieties of colored spinels are quite abundant in Sri Lanka, but white spinels are very rare. Hence, it is highly unlikely that the rough gemstone is a white spinel. Moreover the crystal habit of spinels are octahedral which is not what is seen in the image.
White milky quartz is commonly found in Sri Lanka, and have a shiny appearance like the rough stone you have uploaded. However, because of their cloudiness and opaqueness such quartz stones have no gem value and are not used as gemstones. The crystal habit of quartz is six-sided prism terminating with six-sided pyramids at the ends, like sapphires. Hence the image you have uploaded may be of a milky quartz crystal.
Colorless and white topaz is also quite common in Sri Lanka. Topaz also forms prismatic crystals ending sometimes in pyramidal faces. However, the type of milkiness found in the image is highly unlikely to be that of topaz.
Colorless zircon known as "Matara Zircon" mined in a village in the Matara District of Sri Lanka, is well known in the international gem trade. When cut and polished the "Matara Zircon" has a brilliance and fire very similar to natural diamonds and was known in the trade as "Matura Diamonds." Crystals of zircon are tetragonal or square prismatic and dipyramidal. Comparison of the giant white zircon crystal discovered in Embilipitiya with the image of the rough stone uploaded, shows that the unidentified rough stone is highly unlikely to be Zircon.
White moonstone is common in Sri Lanka, and the image of a white moonstone from Meetiyagoda, Sri Lanka shows that it is not morphologically similar to the image of the white rough stone uploaded by Guru. The moonstone gets an opalescent luster only after cutting and polishing, usually as a cabochon.
Hence the rough white stone uploaded by Guru is most likely to be a milky quartz crystal or a white sapphire rough stone.
Well I don't think it means that. Both SSEF and AGL are internationally recognized gem testing laboratories in the world, with the latest state-of-the-art equipment at their disposal and a massive reference database on sapphires from around the world. The contradictory reports on the same blue sapphire by two recognized laboratories is a very rare occurrence and as I said earlier this comes within the failure rate or negative identification of 20%. The contradictory reports no doubt contributed to the sapphire being assigned a lower pre-sale estimate than that usually assigned to Kashmir sapphires. However, if the owner of the sapphire ring had sought a third opinion from another recognized laboratory, and if this lab too had confirmed that the sapphire was of Kashmir origin, things would have worked out in a different way.
Thanks Mikegem for your sharp observation. We have discussed this problem extensively on October 22, 2012, in reply to a question raised by one of our regular participants on this forum, AnitaP, why some renowned gem testing laboratories like the GIA do not issue Country-of-origin reports on any gemstones including sapphires. (Please refer to page 1 of this thread on Hill's Kashmir Sappire).
During that discussion it was pointed out that despite the advances in science and technology and the availability of advanced analytical methods, making use of modern tools and state-of-the-art equipment such as the Ultra Violet-Visible-Near Infrared spectrometer (UV-ViS-NIR) , the Raman spectroscope, Photo-Acoustic Spectroscopy (PAS), Fourier Transform Infrared Spectrometer (FT-IR), Energy-dispersive X-ray Fluorescence (ED-XRF), Laser-induced Breakdown Spectroscope (LIBS), Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS), and the Scanning Electron Microscope (SEM), only a success rate of around 80% has been achieved in the relatively new field of Geographic Origin Determination. The geographic origin of a given sapphire is determined by collecting all relevant data on the sapphire, such as the nature of the inclusions, optical properties, growth characteristics if any, the nature and concentration of trace elements etc. and comparing it with the properties of a reference sapphire collection, in a database maintained by the Laboratory, containing a sufficiently high number of samples from commercially relevant mining areas and deposits worldwide which include reference stones from exhausted mines or deposits where production has ceased. AGL maintains one of the largest reference databases in the world, consisting data of over 10,000 samples collected from gem mines and deposits situated around the world.
However, there are factors that can complicate Geographic Origin Determination, such as :- 1) Heat treatment that can alter the chemistry of gemstones (Eg. the distinctive color zoning seen in sapphires from Andranondambo, Madagascar, becomes significantly less distinct when the stones are heated); 2) Non-uniformity of characteristics of sapphires even from different areas of the same deposit 3) Discovery of new locations bringing hitherto unknown new materials into the market; 4) the need to maintain a sample of stones that remains current. eg. data collected from one of the best sample populations of Ceylon blue sapphires 20 years ago may not be valid today, and has to be continuously updated from time to time. Since Geographic/Country-of-origin of a gemstone is based more on expert opinion than on conclusive evidence, there is a tendency for labs to differ occasionally, when issuing reports on the same sapphire. Sometimes when too many ambiguities arise, the labs may issue a tentative opinion or no opinion at all. All these difficulties come within the failure rate or negative identification of 20%.
I hope, this explains the discrepancy observed by Mikegem, that the 23.35-carat, cabochon blue sapphire is of Ceylon origin according to the Swiss Gemological Institute, but of Kashmir origin according to American Gem Laboratories. I am sure it was because of this discrepancy that the fairly large and attractive cabochon blue sapphire was assigned a pre-sale estimate within the range of values of Ceylon blue sapphires US$ 45,363 - 71,285 and sold for a slightly enhanced value of US$ 97,129 or ppc-value of only US$ 4,160.
Welcome back to our forums, Mikegem and gemlite, and thanks for your contributions. Kashmir sapphires are still making headlines at public auctions and setting new world records. Its interesting indeed to watch how these rare creations of nature are gaining value day by day, a clear indication of the esteem in which these sapphires are held by connoisseurs and collectors.
The same list of Kashmir sapphires above arranged in descending order of price-per-carat (ppc) values :-
1) 17.16-carat, square emerald-cut, Kashmir blue sapphire - price-per-carat - US$ 236,540 - Sotheby's Hong Kong, October 7, 2014
2) 12.00-carat, rectangular emerald-cut, Kashmir blue sapphire - price-per-carat - US$ 193,839 - Sotheby's Hong Kong, October 7,2014
3) 28.18-carat, square emerald-cut Kashmir Sapphire - price-per-carat - US$ 180,731 -Sotheby's New York, April 2014.
4) 26.66-carat and 20.88-carat, cushion-cut Richelieu Sapphires - price-per-carat - US$ 175,821- Sotheby's Geneva, November 2013.
5) 19.88-carat, cushion-cut "Star of Kashmir" Sapphire - price-per-carat - US$ 175,256-Christie's Geneva, May 2013.
6) 8.91-carat, cushion-cut Kashmir sapphire - price-per-carat - US$ 153,759 -Christie's New York December 2012.
7) 21.42 carat, cushion-cut Kashmir sapphire - price-per-carat - US$ 150,867 - Sotheby's Geneva, November 2013.
14.84-carat and 13.47-carat, cushion-cut Kashmir sapphires - price-per-carat - US$ 146,067 - Christie's Hong Kong May 2011.
9) 26.41-carat, cushion-cut Kashmir sapphire - price-per-carat - US$ 145,342 - Christie's Hong Kong, November 2011.
10) 22.66-carat, cushion-cut Hill's Kashmir Sapphire - price-per-carat- US$ 135,216 - Christie's New York, April 2007.
11) 20.04-carat, cushion-cut Kashmir blue sapphire - price-per-carat - US$ 130,474 - Sotheby's Hong Kong, April 2014
12) 7.68-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$ 121,440 - Sotheby's Hong Kong, April 2013.
13) 10.66-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$ 112,607- Christie's Hong Kong, November 2012.
14) 21.27-carat, oval cabochon-cut, Kashmir blue sapphire - price-per-carat - US$ 98,966 - Christie's New York, December 2013.
15) 9.37-carat, circular-cut, Kashmir blue sapphire - price-per-carat - US$ 94,907 - Christie's Hong Kong, November 2012.
16)11.71-carat, cushion-cut Kashmir blue sapphire - price-per-carat - US$94,822 - Sotheby's Geneva, May 2013.
17) 11.06-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$84,327 - Sotheby's Hong Kong, April 2013.
18) 31.53-carat, cabochon-cut, Kashmir blue sapphire - price-per-carat - US$84,316 - Christie's New York, April 2012
19) 42.28-carat, cushion-shaped Kashmir sapphire - price-per-carat - US$ 81,798 - Christie's Geneva, November 2008.
20) 4.52-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$79,332 - Sotheby's Geneva, November 2013.
21) 6.90-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$64,460 - Sotheby's Geneva, May 2013
22) 12.71-carat, cushion mixed-cut Kashmir blue sapphire - price-per-carat - US$ 61,762 -Sotheby's New York, April 2014.
23) 5.45-carat, oval-cut, Kashmir blue sapphire - price-per-carat- US$53,761 - Sotheby's New York, April 2014.
24) 5.48-carat, cut-cornered step-cut, Kashmir blue sapphire - US$49,920 - Sotheby's Geneva, November 2013.
25) 10.40-carat, sugar-loaf cabochon-cut, Kashmir blue sapphire - price-per-carat - US$43,600 - Sotheby's Hong Kong, April 2013.
26) 9.68-carat, cushion-cut, Kashmir blue sapphire - price-per-carat - US$36,596 - Woolley & Wallis auctions, May 2014
27) 4.53-carat, oval-cut, Kashmir blue sapphire - price-per-carat - US$23,455 - Sotheby's New York, April 2014.
28) 11.15-carat, cushion brilliant-cut, Kashmir blue sapphire - US$11,984 - Saffronart online auction October 31, 2012.
Hence, as at October 7, 2014 the world record for price-per-carat value of Kashmir blue sapphires - US$ 236,540 - is held by the 17.16-carat, square emerald-cut, Kashmir blue sapphire, that sold at Sotheby's Hong Kong, Magnificent Jewels & Jadeite sale held on October 7, 2014.
"Hill's Kashmir Sapphire" has been one of our most popular threads, dealing mainly with all aspects of the rare Kashmir blue sapphires, the benchmark for all blue sapphires originaing from different sources across the world. The thread had registered over 50,000 views, no doubt due to the wealth of information available therein. Hence, we strongly feel that continuing with this thread, giving the latest updates on the performance of these rare blue sapphires at public auctions, is imperative not only as a source of information on blue sapphires, but also to rekindle and strengthen the international blue sapphire market. It is with this intention, that we are re-opening this thread again and as a first step, we are posting the new revised list of Kashmir blue sapphires that appeared at public auctions arranged in descending order of whole stone prices and the same list arranged again in descending order of price-per-carat values. In the revised lists we have incorporated information provided by one of our contributors - rashid - on April 13, 2015, about two record breaking Kashmir blue sapphires, that appeared at Sotheby's Hong Kong Magnificent Jewels & Jadeite Sale on October 7, 2014- Lots 1752 and 1938, whose images have already been upoaded by him.
Revised list of Kashmir blue sapphires that appeared at public auctions arranged in descending order of whole stone prices :-
1) 26.66-carat and 20.88-carat cushion-cut Richelieu Sapphires - US$ 8,358,520 - Sotheby's Geneva, November 2013- Most expensive Kashmir blue sapphires sold at an auction.
2) 28.18-carat, square emerald-cut, Kashmir blue sapphire - US$5,093,000 - Sotheby's New York, April 2014.
3) 14.84-carat and 13.47-carat cushion-cut Kashmir blue sapphires from the pair of sapphire and diamond ear-pendants - US$4,135,165 - Christie's Hong Kong May 2011.
4) 17.16-carat, square emerald-cut, Kashmir blue sapphire - US$ 4,059,031-Sotheby's Hong Kong, October 7, 2014.
5) 26.41-carat, cushion-cut, Kashmir blue sapphire - US$ 3,838,508 - Christie's Hong Kong, November 2011.
6) 19.88-carat, cushion-cut "Star of Kashmir" blue Sapphire - US$ 3,484,102 - Christie's Geneva, May 2013.
7) 42.28-carat, cushion-shaped Kashmir blue sapphire - US$ 3,458,420 - Christie's Geneva, November 2008.
21.42 carat, cushion-cut Kashmir blue sapphire - US$ 3,231,584 - Sotheby's Geneva, November 2013
9) 22.66-carat, cushion-cut Hill's Kashmir blue Sapphire - US$ $ 3,064,000 - Christie's New York, April 2007
10) 31.53-carat, cabochon-cut, Kashmir blue sapphire - US$2,658,500 - Christie's New York, April 2012
11) 20.04-carat, cushion-cut, Kashmir blue sapphire - US$ 2,614,701 - Sotheby's Hong Kong, April 2014
12) 12.00-carat, rectangular emerald-cut, Kashmir blue sapphire - US$ 2,326,078 - Sotheby's Hong Kong, October 7, 2014.
13) 21.27-carat, oval cabochon-cut, Kashmir blue sapphire - US$2,105,000 - Christie's New York, December 2013.
14) 8.91-carat, cushion-cut Kashmir blue sapphire - US$1,370,000 - Christie's New York, December 2012.
15) 10.66-carat, cushion-cut, Kashmir blue sapphire - US$1,200,398 - Christie's Hong Kong, November 2012.
16) 11.71-carat, cushion-cut, Kashmir blue sapphire - US$1,110,370 - Sotheby's Geneva, May 2013.
17) 7.68-carat, cushion-cut, Kashmir blue sapphire - US$932,657 - Sotheby's Hong Kong, April 2013.
18) 11.06-carat, cushion-cut, Kashmir blue sapphire - US$932,657 - Sotheby's Hong Kong, April 2013.
19) 9.37-carat, circular-cut, Kashmir blue sapphire - US$889,280 - Christie's Hong Kong, November 2012.
20) 12.71-carat, cushion mixed-cut, Kashmir blue sapphire - US$785,000 - Sotheby's New York, April 2014.
21) 10.40-carat, sugar-loaf cabochon-cut, Kashmir blue sapphire - US$453,446 - Sotheby's Hong Kong, April 2013.
22) 6.90-carat, cushion-cut, Kashmir blue sapphire - US$444,775 - Sotheby's Geneva, May 2013
23) 4.52-carat, cushion-cut, Kashmir blue sapphire - US$358,580 - Sotheby's Geneva, November 2013.
24) 9.68-carat, cushion-cut, Kashmir blue sapphire - US$354,249 - Woolley & Wallis auctions, May 2014
25) 5.45-carat, oval-cut, Kashmir blue sapphire - US$293,000 - Sotheby's New York, April 2014.
26) 5.48-carat, cut-cornered step-cut, Kashmir blue sapphire - US$273,567 - Sotheby's Geneva, November 2013.
27) 11.15-carat, cushion modified brilliant Kashmir blue sapphire - US$133,623 - saffronart online auction October 31, 2012.
28) 4.53-carat, oval-cut Kashmir blue sapphire - US$106,250 - Sotheby's New York, April 2014
After being offline for some time due to unforeseen circumstances, the popular jewelry forum, forums.internetstones.com is once again live and active. While thanking our multitude of members and followers for the keen interest depicted in our fora previously, and for their valuable contributions in maintaining its interesting and vibrant nature, initiating new threads and contributing to on-going threads, once again, we take this opportunity to invite all our loyal members, to actively contribute to the development of this important forum, catering to the jewelry industry. Our discussions had been very informative, and some of the comments made were by experts in their own field, who had posted under various pseudonyms. It is our fervent hope and prayer that all of them without exception, would return back to our forums, and again contribute to its re-invigoration.
Factor 3 above - Lots set predominantly with diamonds - appears to be the main reason why the lot was assigned a higher estimate and as expected also sold slightly above the upper estimate, even though the piece was not a signed jewel. Besides this, the use of emerald-cut emeralds as the centerpiece of each flower and the design features of the flower bracelet, might also have had an impact on the final price achieved by Lot 8.
Thanks AnitaP for your intelligent observation, and thanks Joan for your appropriate comment. I totally agree with you Joan on your comment. The blue sapphire market is indeed becoming stronger and stronger, as reflected not only by the high prices achieved by Kashmir sapphires at public auctions, but also by fine Burma and Ceylon sapphires, that are also setting new milestones at public auctions, such as the staggering US$17.7 million achieved by 392.52-carat, cushion-cut, Ceylon sapphire, "The Blue Belle of Asia Sapphire," that shattered the world record for any sapphire sold at an auction.
Of the three RBC diamonds you have mentioned Joan, The Graff Constellation diamond is yet to be sold, the Safiya diamond was sold by Graff in September 2000, to an unidentified Middle-Eastern buyer, however, the identity of the purchaser and the price of purchase was not revealed. Hence, we are left only with the Chloe diamond, which was sold at a Sotheby's Magnificent Jewels auction held in Geneva, on November 14, 2007, nearly eight years ago, for US$ 16,189,769 million (18.2 million Swiss francs). At that time the 84.37-carat Chloe diamond set several auction records, such as the largest, D-Color, flawless, round brilliant-cut diamond ever sold at an auction; the second most expensive jewel ever auctioned, the first being the 100.1-carat, D-color, pear-shaped, internally flawless, "Star of the Season" diamond which was sold in 1995, also by Sotheby's for US$16.5 million, to the Saudi-based renowned jeweler and diamond collector, Sheik Ahmed Hassan Fitaihi; the highest price-per-carat ever paid for a D-color, flawless/internally flawless diamond at an auction. The price-per-carat of the chloe diamond works out to US$191,890. In comparison the price-per-carat of the "Star of the Season" diamond was only US$ 164,835.
It is important to note that the whole stone price as well the price-per-carat of the 84.37-carat Chloe diamond was in accordance with the market values applicable in the year 2007 and hence may not be used for comparison with the price-per-carat value of diamonds sold in the year 2015. Like colored diamonds, whole stone prices as well as price-per-carat values of D-color, flawless/internally flawless diamonds, also have significantly increased particularly after the Great Recession of 2008/2009, when investors sought for safe havens to invest their money. The world record price-per-carat values of US$240,500 and US$246,710 realized respectively by the 28.86-carat and 25.32-carat D-color, flawless/internally flawless RBC diamonds is a reflection of the significant increase that took place after year 2009. Hence, the actual PPC-values of the Chloe-diamond, Safiya diamond, the Graff Constellation diamond or any other comparable RBC diamond will be known only when such a diamond appears at a public auction.
@themonetaryman Thank you very much.
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Thank you "themonetaryman" for revealing the actual aim of your original question seeking information on D-color RBC diamonds of clarity grade IF/FL above 50 carats in weight. While wishing you Good Luck in your quest for the rare diamond, I feel that we should thank you profusely for your contribution, as it has generated a discussion on various aspects of large D-color round brilliant-cut diamonds, such as there scarcity etc. I also feel that this thread on RBC diamonds would help to bring into focus all such diamonds that have performed extremely well at public auctions, including those that are less then 50 carats in weight. I invite all active contributors to our forums to help bring such RBCs to this forum and highlight their existence. Thank you !
Large D_color, Flawless or Internally Flawless round brilliant-cut diamonds are indeed very rare as diamond cutters normally tend to pick a shape/cut to suit the shape of the rough diamond, in order to minimize losses. In other words they try to maximize for both quality and quantity, rather than maximizing for quality at the expense of quantity. Hence, shapes/cuts other than round brilliant-cut are common among large diamonds, such as oval brilliant-cut, pear-shaped brilliant cuts, heart-shaped brilliant-cuts, cushion-cut, emerald-cut, asscher-cut, radiant-cut etc. As an example we can take the cutting of the 102.79-carat round brilliant-cut Graff Constellation diamond from the 478-carat "Light of Letseng" rough diamond. After a thorough study of the rough diamond by a team of engineers, gemologists and master cutters and polishers of DIAMCAD using the most advanced scanning technology, it was finally decided to cut the rough diamond into six, one main round brilliant-cut diamond and five satellite diamonds - one smaller round brilliant-cut, a heart-shaped diamond, two pear-cut diamonds and a marquise-cut diamond. The largest diamond created was the 102.79-carat, round brilliant-cut Graff Constellation diamond.The second largest was the 51.20-carat heart-shaped diamond. Four other tiny diamonds were also created from the corners of the rough stone, making a total of 9 satellite diamonds. Hence, in creating the round brilliant-cut Graff Constellation, 9 other satellite diamonds were also created at the same time.
In the case of the Light of Letseng rough diamond, the creation of 9 satellite diamonds was possible because of the high quality of the rough diamond. Thus wastage of diamond in cutting was a minimum. If the rough diamond was not of very good gem quality the creation of so many satellite diamonds would not be possible, and there would be enormous wastage in cutting the main diamond.
You have rightly mentioned the three main famous round brilliant-cut diamonds in existence, viz. the 84.37-carat Chloe Diamond, 90.97-carat Icon/Safiya Diamond and the 102.79-carat Graff Constellation Diamond. There are not many D-color, IF/FL, round brilliant-cut diamonds above 50 carats in existence. A round brilliant-cut diamond weighing 103.46 carats cut and polished by Graff and mounted on a platinum ring appeared at a Sotheby's Geneva sale held on May 13, 2014. But the diamond is N-color and SI-1 clarity and sold for US$4.8 million. However, there are quite a number of D-color, IF/FL round brilliant-cut diamonds between 10 to 50 carats that appeared at public auctions and performed significantly well.
It will be interesting to have the images of the 1st, 2nd and 3rd largest D-color, Internally- Flawless, round brilliant-cut diamonds -the Graff Constellation, the Safiya and the Chloe diamonds side by side for comparison.
Hi ridhaanya, nothing can be said about this sapphire unless the actual weight of the stone is known. You can go to our thread on Significant-Burma-Mogok-Blue-Sapphires-that-appeared-at-public-auctions, and get an approximate idea about the value of your stone.
The two conditions of lighting to observe a color change in alexandrites are 1) natural daylight/fluorescent light and 2) Incandescent light. The color in natural daylight can be green/bluish-green/yellowish-green/teal-blue etc. and the color in incandescent light can be purple/reddish-purple/purplish-red/brownish-red/reddish-brown/brownish-purple etc. depending on the source of the alexandrite.
The photograph of natural daylight can be taken in diffused sunlight either indoors or outside in the shade, and not in direct sunlight. An image taken under fluorescent lighting should also show the same colors as natural daylight. The other photograph should be taken under incandescent lighting indoors. An incandescent light bulb is an electric light which produces light when its filament gets heated to a high temperature by an electric current.
It's always ideal to have a white background for your images, instead of a colored background that can tend to mask the actual color of the stone. Mohammed, the first image you have taken indoors under natural daylight shows a tinge of green color expected in an alexandrite, but the color appears to be masked by the ash-colored background of the image. Try repeating this under natural daylight indoors with the alexandrite placed on a white sheet of paper. The second photograph should also be taken with the alexandrite placed on a white sheet of paper but an incandescent light directed at the stone, from a table lamp or other suitable source. Make sure you cut off all natural daylight when you are taking the second photograph.
List of Burma blue sapphires considered so far, arranged in descending order of whole stone prices
1) 114.73-carat, oval-cut, Burma blue sapphire that sold at Sotheby's Geneva Magnificent Jewels Sale, held on November 13, 2013 for US$7,137,821. Price-per-carat USD 62,214.
2) 62.02-carat, rectangular step-cut Burma/Mogok sapphire, known as the Rockefeller Sapphire, that sold at a Christie's New York auction on April 11, 2001 for USD 3,031,000. Price-per-carat value - US$ 48,871.
3) 7.57-carat and 6.85-carat, cushion-cut Burma blue sapphires from a matching pair of sapphire and diamond earclips that sold for US$ 129,427, at Sotheby's Geneva on November 13, 2013. PPC value US$8,975
4) 13.21-carat, oval-cut Burma blue sapphire that sold for US$61,308 at Sotheby's Geneva on November 13, 2013. PPC value US$4641.
5) 14.89-carat, cushion-cut, Burma blue sapphire that sold for US$169,000 at Christie's New York Rockefeller Plaza Magnificent Jewels Sale held on October 16, 2007. PPC value US$11,350.
6) 16.38-carat, cushion-cut, Burma sapphire, that sold for an impressive US$484,764 at Christie's Jewels : The Hong Kong Sale held on May 26, 2009. PPC value US$29,595.
7) 9.06-carat and 8.42-carat, oval cabochon-cut Burma blue sapphires, set on a matching pair of sapphire ear-pendants that sold for US$56,707 at Christie's Jewels : The Hong Kong Sale held on May 26, 2009. PPC value US$3,244.
The above list arranged in descending order of price-per-carat values :-
1) 114.73-carat, oval-cut, Burma blue sapphire - PPC value US$62,214
2) 62.02-carat, rectangular step-cut Burma/Mogok sapphire, known as the Rockefeller Sapphire. PPC value US$48,871.
3) ) 16.38-carat, cushion-cut, Burma blue sapphire - PPC value US$29,595.
4) 14.89-carat, cushion-cut, Burma blue sapphire - PPC value US$11,350.
5) 7.57-carat and 6.85-carat, cushion-cut BurmPPC value US$4641.a blue sapphires - PPC value US$8,975
6) 13.21-carat, oval-cut Burma blue sapphire - PPC value US$4641.
7) 9.06-carat and 8.42-carat, oval cabochon-cut Burma blue sapphires - PPC value US$3,244