An Alexandrite of Russian origin sets world auction record for an Alexandrite at Christie's Geneva May 14,2014 Magnificent Jewels sale

The emerald-like green color in natural daylight and amethyst-like purple/violet color in artificial light is indeed fantastic in the images uploaded by gemlite. The rarity of alexandrites and their superior color-changing qualities have made alexandrites one of the most sought after and valued gemstones in the world today.

The unmounted 21.41-carat, cushion-cut alexandrite is certified as of Russian origin, both by the SSEF and LFG. Given this fact, this alexandrite is without any doubt of late 19th or early 20th century origin, the period during which most of the alexandrite deposits of the Ural mountains in Russia was exploited and finally depleted. George Frederick Kunz, gemologist of Tiffany & Co visited the Ural mountains in the late 19th-century, and purchased most of the alexandrites mined during this period on behalf of his company. These alexandrites were incorporated as the centerpiece of many jewelry pieces designed by Tiffany & Co. during this period. Most of these late 19th-century and early 20th-century jewelry pieces incorporating Russian alexandrites are now in family vaults and passed down from generation to generation, and rarely make their appearance at public auctions.
The 21.41-carat, cushion-cut Russian alexandrite is one such rare appearance of a late 19th or early 20th-century alexandrites, mined at the Ural mountains in Russia and perhaps personally handled by George Frederick Kunz himself.

Any alexandrite over 10 carats in weight is beyond rare. The alexandrite highlighted by gemlite is more than double this limit, which further enhances its rarity. Alexandrites of Russian origin are extremely rare and almost non-existent today. Premium values are attached to these rare Russian alexandrites, if their Russian origin can be established beyond any doubt. This explains, the record-breaking price of US$ 1,495,395 realized by the 21.41-carat Russian alexandrite at the Christie's Geneva Magnificent Jewels Sale held on May 14, 2014. The price-per-carat value achieved by this alexandrite is US$ 69,845.

A 19.05-carat, cushion-cut, Brazilian alexandrite set as the centerpiece of a platinum ring with a pave-set diamond surround and shoulders, appeared at Christie's New York Magnificent Jewels Sale held on October 16, 2007. GGL which certified its country of origin, also spoke highly of several outstanding characteristics possessed by this stone, such as its high degree of transparency and strong color-change effect from bluish-green in daylight to reddish-purple when exposed to incandescent light. GGL also stated that such a combination of high clarity and strong color-change effect, in a Brazilian alexandrite exceeding 15 carats, is very rare. A pre-sale estimate of USD 550,000 - 650,000 was placed on this rare alexandrite ring, which sold much above the upper estimate for USD 959,400 equivalent to USD 50,362 per carat.

Another 18.23-carat, cushion-cut alexandrite of Ceylon/Sri Lanka origin mounted on a platinum ring and flanked on either side by a triangular-cut diamond, appeared at Christie's New York Magnificent Jewels Sale, held on October 15, 2013. The alexandrite was certified by AGL as of classic Ceylon/Sri Lanka origin, which also attested to its rarity and superior color-change effect. A pre-sale estimate of US$400,000-600,000 was placed on this alexandrite ring, which was sold within the estimate for US$557,000 equivalent to US$30,554 per carat.

A stunning Brazilian alexandrite weighing just 11.66 carats and mounted on a platinum ring appeared at the Christie's Geneva Magnificent Jewels Sale held on November 16, 2011. SSEF certified not only the Brazilian origin of the stone, but also the mine-of-origin as Hematita Mine in Brazil. Both SSEF and GGL certified the natural origin of the stone,without any treatment, as well as its high clarity and strong color-change effect. A pre-sale estimate of US$351,624 - 494,471 was placed on this ring which sold within the estimated range for US$421,501. This works out to a PPC of US$36,149.
Another alexandrite from Hematita with its characteristic and attractive color change, cushion-cut and weighing 15.58 carats, mounted on a platinum ring with an oval-shaped diamond surround, appeared at Christie's Hong Kong Magnificent Jewels Sale held on May 29, 2012 and registered an enhanced price of US$934,480 above the pre-sale estimate of US$ 590,000 - 840,000. This works out to a PPC of US$ 59,979. A GGL report accompanying this stone speaking highly of its characteristics reads as follows :-
This exceptional gemstone displays a saturated and homogeneous colour combined with a very high degree of transparency. The well-proportioned cut provides many internal vivid colour reflections, enhanced by a pronounced colour change effect from bluish-green when viewed in daylight, to reddish-purple upon exposure to incandescent light. Such a combination of high clarity and strong colour-change effect, in a Brazilian alexandrite exceeding 15 carats is very rare

In October 2011, at Christie's New York Magnificent Jewels Sale, another rare Ceylon alexandrite made its appearance. This cushion-cut alexandrite weighed 10.41 carats and was mounted on a platinum ring, with half moon and tapered baguette-cut diamond shoulders. The lot was accompanied by an original invoice from J.E. Cladwell & Co. dated October 16, 1943. AGL certified the Ceylon origin of the stone and its natural untreated status. The ring sold for US$ 182,500 much above the pre-sale estimate of US$30,000 - 50,000. The PPC value of the stone is US$ 17,531.

Three important sources of alexandrites in the world have emerged from the above discussion - Russia, Ceylon/Sri Lanka and Brazil. The six stones highlighted by our participants belong to one of these three sources. The actual breakdown is one Russian, two Sri Lankan and three Brazilian.
The following is the list of the six alexandrites arranged in descending order of their whole stone prices fetched at the auctions :-
1) 21.41-carat, cushion- cut alexandrite of Russian origin - US$ 1,495,395
2) 19.05-carat, cushion-cut alexandrite of Brazilian origin - US$ 959,400
3) 15.58-carat, cushion-cut alexandrite of Brazilian origin - US$ 934,480
4) 18.23-carat, cushion-cut alexandrite of Ceylon/Sri lanka origin - US$ 557,000
5) 11.66-carat, cushion-cut alexandrite of Brazilian origin - US$ 421,501
6) 10.41-carat, cushion-cut alexandrite of Ceylon/Sri Lanka origin - US$ 182,500

List of the above alexandrites arranged in descending order of price-per-carat values :-
1) 21.41-carat, cushion- cut alexandrite of Russian origin - PPC value US$ 69,845
2) 15.58-carat, cushion-cut alexandrite of Brazilian origin - PPC value US$ 59,979
3) 19.05-carat, cushion-cut alexandrite of Brazilian origin PPC value US$ 50,362
4) 11.66-carat, cushion-cut alexandrite of Brazilian origin - PPC value US$ 36,149
5) 18.23-carat, cushion-cut alexandrite of Ceylon/Sri lanka origin - PPC value US$ 30,554
6) 10.41-carat, cushion-cut alexandrite of Ceylon/Sri Lanka origin - PPC value US$ 17,531

The above analysis shows that both in terms of whole stone prices and price-per-carat values, there is a market ranking for alexandrites based on origin, like blue sapphires. Highest prices are fetched by Russian alexandrites, whenever such stones appear at auctions, followed by Brazilian (Hematita) and Ceylon/Sri Lanka alexandrites. This ranking is clearly brought out for PPC values than whole stone prices.
That such a ranking does exist for alexandrites will be confirmed only after more alexandrites appearing at public auctions are highlighted.
The oldest source of alexandrites in the world is Russia, where the gemstone was first discovered in 1830 during the reign of Czar Nicholas I, coincidentally on the birthday of Alexander II, the Czar's son and heir, in whose honor the new discovery was named. Interestingly, the colors green and red, involved in the dramatic color-change effect, observed in these stones (green in natural daylight to red in artificial incandescent light) were the colors of the Russian Imperial Guard, and hence the significance of this discovery for the Romanov rulers of Russia.
The next oldest source of alexandrites in the world is Ceylon/Sri lanka and India, where the gemstone was discovered after the depletion of the Ural mountain deposits in the early 20th-century. The original invoice from J.E.Cladwell & Co. for the 10.41-carat Ceylon alexandrite ring dated 1943, gives an indication of the possible period when these gemstones were discovered in Sri Lanka. The high-quality Hematita deposits in Nova Era, Brazil, was discovered only in 1987. Tanzania and Madagascar deposits are the most recently discovered alexandrite deposits in the world.

One of the most stunning alexandrites to appear at a public auction, was the 15.35-carat, cushion modified brilliant-cut alexandrite, that appeared at the Government Auction Assets sale of over 1,500 items held online at the online auction site LiveAuctioneers, on Sunday, April 29, 2012. This is perhaps one of the largest cushion modified brilliant-cut alexandrites in existence, appearing bright green in natural daylight and changing to golden-yellow in incandescent light.
“An alexandrite stone of this quality and size is highly sought after by gemstone experts, connoisseurs and investors alike,” said Government Auction’s chief auctioneer Paul Sabesky, referring to the top lot of his upcoming sale. With certification from the Gemological Institute of America (GIA), it has an estimated value of US $83,580-$167,160. The GIA in keeping with its policy has not ventured to give the country-of-origin of this beautiful alexandrite.

Several alexandrites appeared at Sotheby's auctions in the years 2010, 2011 and 2012. Two alexandrites featured in 2010, one at Sotheby's New York Magnificent Jewels Sale in April 2010 and the other also at Sotheby's New York in December 2010. In October 2011, another alexandrite appeared at Sotheby's Hong Kong, Magnificent Jewels & Jadeite Sale and again in December 2012 at Sotheby's New York, Magnificent Jewels Sale.

The alexandrite that featured at Sotheby's New York in April 2010 is a 15.86-carat, cushion antique modified mixed-cut Sri Lanka alexandrite, mounted on a platinum ring and flanked on either side by a modified shield-shaped diamond. AGL certified that the stone is a natural Sri Lanka alexandrite with a strong color change. The lot sold for USD 104,500 which was 2.3 times the lower estimate of USD 45,000 and 1.9 times the upper estimate of USD 55,000.

At Sotheby's New York in December 2010, another Sri Lanka alexandrite, oval-shaped and weighing 10.16 carats featured as Lot 356. The rare gemstone was set as the centerpiece of a platinum ring designed by Oscar Heyman & Bros.and was surrounded by a row of oval-cut diamonds. A pre-sale estimate of USD 50,000-70,000 was placed on the lot, which sold exactly at the lower estimate of USD 50,000. AGL certified the Sri Lankan origin of the stone and rated the quality of color change from very good to excellent.

The alexandrite that appeared at Sotheby's Hong Kong Jewels & Jadeite Sale in October 2011, was a 12.00-carat, oval-cut stone of unknown country-of-origin. The alexandrite was set as the centerpiece of a white and yellow gold ring with a butterfly and floral motif surround, set with brilliant-cut colorless, yellow and brown diamonds totaling 1.40 carats. A GRS report certified the natural origin of the stone and its prominent color change from greenish-blue in natural daylight to red in incandescent light. A special comment in the report read as follows :- "very rare combination of size, excellent colour-change, very good clarity and brilliance." The report however, did not specify the country-of-origin of the alexandrite. The lot sold for USD 203,794 within the estimated range of USD 167,679 - 206,374.

The alexandrite that featured at Sotheby's New York in December 2012, was a relatively small stone weighing only 4.50 carats, but certified as Russian origin, set as the centerpiece of a platinum ring by Raymond Yard circa 1925, flanked by four trapezoid shaped diamonds and 16 round diamonds. AGL certified the stone as of Russian origin with a strong color change. A pre-sale estimate of only USD 25,000 to 35,000 was placed on the ring which sold for a much enhanced price of USD 170,500 in keeping with its Russian origin.

Thanks Peter for your updates. I think we can now incorporate these four alexandrites in our list given above and produce a revised list both for whole stone prices and price-per-carat values.

The revised list of 10 alexandrites arranged in descending order of whole stone prices is as follows :-

1) 21.41-carat, cushion- cut alexandrite of Russian origin - US$ 1,495,395
2) 19.05-carat, cushion-cut alexandrite of Brazilian origin - US$ 959,400
3) 15.58-carat, cushion-cut alexandrite of Brazilian origin - US$ 934,480
4) 18.23-carat, cushion-cut alexandrite of Ceylon/Sri lanka origin - US$ 557,000
5) 11.66-carat, cushion-cut alexandrite of Brazilian origin - US$ 421,501
6) 12.00-carat, oval -cut alexandrite of unknown country-of-origin - US$ 203,794
7) 10.41-carat, cushion-cut alexandrite of Ceylon/Sri Lanka origin - US$ 182,500
4.50-carat,cushion-cut alexandrite of Russian origin - US$ 170,500
9) 15.86-carat, cushion antique mixed-cut alexandrite of Ceylon/Sri Lanka origin - US$ 104,500
10) 10.16-carat, oval-cut alexandrite of Ceylon/Sri Lanka origin - US$ 50,000

The revised list of above alexandrites arranged in descending order of price-per-carat values :-
1) 21.41-carat, cushion- cut alexandrite of Russian origin - PPC value US$ 69,845
2) 15.58-carat, cushion-cut alexandrite of Brazilian origin - PPC value US$ 59,979
3) 19.05-carat, cushion-cut alexandrite of Brazilian origin PPC value US$ 50,362
4) 4.50-carat, cushion-cut alexandrite of Russian origin - PPC value US$ 37,888
5) 11.66-carat, cushion-cut alexandrite of Brazilian origin - PPC value US$ 36,149
6) 18.23-carat, cushion-cut alexandrite of Ceylon/Sri lanka origin - PPC value US$ 30,554
7) 10.41-carat, cushion-cut alexandrite of Ceylon/Sri Lanka origin - PPC value US$ 17,531
12.00-carat, oval-cut alexandrite of unknown country-of-origin -PPC value US$ 16,982
9) 15.86-carat, cushion antique mixed-cut alexandrite of Ceylon/Sri Lanka origin - PPC value US$ 6,588
10) 10.16-carat, oval-cut alexandrite of Ceylon/Sri Lanka origin - PPC value US$ 4,921

The revised list shows that the market ranking established earlier - Russia, Brazil and Ceylon - still largely holds good, especially for PPC values. The 4.50-carat cushion-cut Russian alexandrite, performed extremely well selling for US$ 170,500, doing better than the larger 15.86-carat and 10.16-carat alexandrites of Ceylon/Sri Lanka origin, which sold only for US$ 104,500 and US$ 50,000 respectively. However, being a smaller stone the 4.50-carat Russian alexandrite could not achieve the PPC value of nearly US$ 70,000 achieved by the 21.41-carat, cushion-cut Russian alexandrite that broke the world record price for an alexandrite by selling for US$ 1,495,395. It however achieved a fairly significant PPC value of US$ 37,888 falling in the 4th-place in the list based on PPC values.

The 15.35-carat, cushion modified brilliant-cut alexandrite, that appeared at the Government Auction Assets sale held online on April 29, 2012 and highlighted by Yousuf, was certified by GIA as an alexandrite. The GIA certificate described its color change as Brownish Green-Yellow to Brown-Yellow. This means that apart from green to bluish-green in daylight and red to purplish-red in incandescent light, shown by fine alexandrites other color changes are also possible in lesser quality alexandrites. What is the chemistry behind these dramatic color changes and what are the ranges in color changes possible in alexandrites ?

The first alexandrites discovered in the Ural Mountains in Russia in 1830 are of the finest quality displaying vivid hues and dramatic color change. The Ural mountain deposits were exploited intensively during the late 19th and early 20th centuries, and were exhausted within a very short period. However, these alexandrites have set the quality standard for alexandrites worldwide, just as much as the Kashmir sapphires discovered accidentally around 1880 in the Paddar region of Kashmir and exploited intensively in 1882 to 1887 and exhausted and abandoned subsequently, has set the world standard for blue sapphires.
Fine quality Ural mountain alexandrites are green to bluish green in daylight and red to purplish red/reddish purple in incandescent light. Their color saturation is moderately strong to strong. Stones that are too light do not reach the quality of color intensity seen in fine-quality gems. Stones that are too dark lack brightness and appear almost black.
Sri Lankan alexandrites are generally larger than their Russian counterparts, but their colors tend to be less desirable. The greens tend to be yellowish compared to the blue-green of the Russian stones, and the reds of Sri Lankan alexandrite are typically brownish red/reddish-brown rather than purplish red.
Alexandrites from Brazil, especially from the Hematita mine, have colors and color change effect that can rival the Ural mountain stones, eg. the 15.58-carat, cushion-cut Brazilian alexandrite dealt with above, that has a saturated, homogeneous color and high degree of transparency, with a pronounced color change effect from bluish-green to reddish-purple.
The 15.35-carat, cushion modified brilliant-cut alexandrite highlighted by Yousuf, has a brownish Yellow-Green color in daylight and a brown-yellow or golden-yellow color in incandescent light. The low saturation in both green and red colors makes the stone brownish both in daylight and incandescent light, which is undesirable for an alexandrite. The color change in this case is also less pronounced, but the high clarity, good transparency and the modified brilliant-cut of the stones, seem to compensate for this, imparting to the stone a bright and brilliant appearance, both in daylight and incandescent light.
Alexandrite is a variety of the mineral chrysoberyl, an aluminate of beryllium with the formula BeAl2O4. Chrysoberyl is the 3rd-hardest material on earth after diamond (10) and corundum (9), with a hardness of 8.5 on the Mohs scale. Ordinary chrysoberyl is yellowish-green and transparent to translucent, and sometimes referred to as chrysolite. When a few atoms of aluminium in the crystal structure of chrysoberyl is replaced by chromium atoms, the variety of chrysoberyl known as alexandrite is produced. The presence of chromium atoms in the crystal structure causes intense absorption of light over a narrow range of wavelengths in the yellow region of the spectrum. This absorption band in the region 580 nm (nano-meter) allows alexandrite to shift from red to green or vice versa when viewed under different light sources.
The color change from red to green or vice versa is due to strong absorption of light in a narrow yellow portion of the spectrum, while allowing large bands of blue-green and red wavelengths to be transmitted. Which of these prevails to give the perceived hue depends on the spectral balance of the illumination. Fine-quality alexandrite has a green to bluish-green color in daylight (relatively blue illumination of high color temperature), changing to a red to purplish-red color in incandescent light (relatively yellow illumination)