Posts by Lareef

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)

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 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.

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.

Thanks gemlite for your valuable contribution.

The extensive account of rubies found in Sri Lanka in the 14th-century, by Ibn Batuta, establishes the fact that Sri Lanka was the primary source of rubies in the world since very ancient times, until the discovery of Mogok rubies in the 16th-century. Batuta stresses the fact that the ruby and carbuncle were found only in Sri Lanka. Batuta's observations that most women in Sri Lanka wore strands of ruby beads on their hands and legs; the white elephant adorned with seven large rubies each of which was larger than a hen's egg; a saucer made of rubies belonging to the king in which oil of aloe was kept, seem to indicate that at one time rubies were found in abundance in the island nation, though now they are very scarce due to continuous exploitation. However, some of these rubies might well have been red spinels also found abundantly in the island. In Badakhshan, in Afghanistan, most of the large red gemstones believed to be rubies at first were subsequently shown to be red spinels. The difference between rubies and spinels became apparent only during the 18th-century, though in countries like Sri Lanka with an ancient cutting and polishing industry, such differences might have been known by ancient cutters and polishers, from the hardness of the two materials, evident from the ease of cutting and polishing the two variety's of gemstones.

An examination of the above excerpt by even the most casual reader shows clearly that interwoven into the tales and fables, are real geographical facts, such as the 4th-paragraph, about Serendib (Sri Lanka) being situated on the equinoctial line, with days and nights being equal in length. The mountain in the middle of the island is a reference to Adam's Peak, the place to which Adam was banished out of paradise, according to ancient Islamic beliefs. The city at the end of a beautiful valley, probably refers to the city of Ratnapura, the "City of Gems." The reference to rubies and other precious stones in the land surrounding Adam's peak, is a reference to the Kalu Ganga basin, the first source of rubies and sapphires in the world, before the discovery of Mogok rubies in the 16th-century. The reference to rare plants growing abundantly is also very accurate, as the Adam's Peak Wilderness, a recently declared World Heritage Site is famous for its extremely rare plant species, some of which are endogenous to the region. Divers seeking for pearls on the seashore, and at the mouths of rivers, is also an accurate reference to the pearl beds situated closer to the mouths of rivers such as Kala Oya and Aruvil Aru in the Bay of Kondatchchy in the Gulf of Mannar, just below the Mannar island.

The King of Serendib, before whom walk a thousand elephants, also seem to be a fairly accurate statement, as remnants of such Royal processions take place to this day in Sri Lanka, such as the internationally renowned Kandy Perehera, organized by the "Temple of the Tooth" annually, in which hundreds of elephants adorned with lavish garments, and colorfully decorated and illuminated with electric bulbs, take part, walking in procession before the king, represented presently by the "Diyawadene Nilame" of the "Temple of the Tooth."

Among the gifts sent by the king of Serendib, to Caliph Harun-al-Rashid was a goblet carved out of a huge ruby, an obvious reference to a large non gem-quality corundum crystal, usually employed for carvings. The ruby goblet full of high-quality Sri Lankan pearls, was among the valuable gifts sent to the Caliph. The description of State processions, with the king riding on the back of an elephant preceded by men on horseback clad in gold brocade and silk appears to be fairly accurate.

Sindbads sixth voyage was to Serendib, as the island of Ceylon (Sri Lanka) was then known to the Arabs. This voyage ended in disaster, when monsoon winds drove his ship towards the base of a mountain rising sheer from the sea. The ship was dashed to pieces, but the crew managed to scramble to safety. In some versions of the story, this mountain is described as a lodestone, or magnetic rock. Many ancient writers referred to a magnetic rock in the Indian Ocean and told of how ships with iron fastenings were attracted to it. Palladius, in the fourth century, even advised that vessels sailing for Serendib should be fastened with wooden pegs.

With no possibility of scaling the mountain, Sindbad and his shipmates abandoned themselves to their fate. Soon they started to die of tropical fever. Sindbad discovered a river that flowed out of sight beneath a rocky archway. Exploring further, he saw that the area around this subterranean river was encrusted with diamonds, rubies and emeralds. After burying the last of his companions, Sindbad built a raft, collected some of the gems and floated off into the darkness of the tunnel. Hours of perilous travel passed. He fell asleep and later awoke to find himself in a beautiful country surrounded by friendly-looking people.

Sindbad awoke after his river journey to find himself surrounded by Serendibian farmers who had come to irrigate their fields. On hearing his adventures, the farmers insisted that he be presented to their king, so they all set off to the City of Serendib. The king proved to be so delighted with Sindbads adventures that he ordered them written in letters of gold and placed in the archives. Sindbad was provided with a chamber inside the palace and a retinue of slaves. He had an audience with the king every day; the rest of the time he amused himself by touring the city and countryside. His description of the island has recognizable elements.

Serendib being situated on the equinoctial line, the days and nights there are of equal length, the mariner stated. The chief city is placed at the end of a beautiful valley, formed by the highest mountain, which is in the middle of the island. I had the curiosity to ascend to its very summit, for this was the place to which Adam was banished out of Paradise. Here are found rubies and many precious things, and rare plants grow abundantly. On the seashore and at the mouths of rivers, divers seek for pearls.

But Sindbad soon grew homesick and requested the king to allow him to return to Baghdad. Eventually the king consented and entrusted Sindbad with a royal present and letter for Haroun al-Rashid. The kings letter was written in blue characters upon a rare parchment. It began: The King of Serendib, before whom walk a thousand elephants, who lives in a palace, of which the roof blazes with a hundred thousand rubies, to the Caliph Haroun al-Rashid, sends greetings. Though the offering we present to you is unworthy of your notice, we pray you accept it as a token of our esteem and friendship for you.

The royal gift was anything but unworthy of notice. It consisted of a fabulous goblet, or grail, carved from a huge ruby and lined with the choicest pearls, and an enormous snake skin with spots the size of a large coin, which would preserve from sickness all those who slept on it. Then there were large quantities of aloes wood and camphor. Lastly, there was a beautiful slave girl who shone like the moon.
On his return to Baghdad, Sindbad conveyed these gifts to the caliph, who demanded to know whether the king of Serendib was really as rich and powerful as he claimed to be. Nothing can equal the magnificence of the kings palace, replied Sindbad. For state processions a throne is set for him upon a huge elephant. On this elephants neck sits an officer, his golden lance in hand, and behind him another bearing a great mace of gold, at the top of which is an emerald as long as my hand. A thousand men on horseback clad in gold brocade and silk go before him.

The caliph was well satisfied with Sindbads report and sent him home. It was not long, however, before the caliph summoned Sindbad and commanded him to deliver a letter and present to the king of Serendib. Reluctant though he was, Sindbad set out on his seventh and last voyage. He sailed uneventfully to Serendib, was greeted by the king with great joy and displayed the caliphs gifts. They included a sumptuous bed with gold hangings, 50 robes of rich embroidery, an agate goblet carved with an archer aiming at a lion and a priceless table that had once belonged to King Solomon.

Thanks Sunil for enlightening us on the use of the word "Ruby" in ancient and modern times.
Ruby and Sapphire were considered as different minerals in ancient times. It was only in 1802 that the French mineralogist Count de Bouron showed by chemical analysis that Ruby and Sapphire belonged to the same group of minerals called Corundum, and were actually crystalline forms of Aluminium oxide. He showed that different colors in Corundum was caused by some of the Aluminium atoms in the Corundum crystal being displaced by atoms of different transition elements. The red color of rubies were shown to be caused by chromium and iron atoms displacing some of the aluminum atoms in the crystal lattice of aluminum oxide. The different colors of sapphires on the other hand were shown to be caused by other transition elements, such as titanium and iron causing different shades of blue; vanadium causing purple color; iron causing yellow and green; nickel causing green; iron and vanadium causing orange; chromium and iron causing the pinkish orange of Padparadscha and white caused by the absence of any transition element.
The cause of the red color in rubies is chromium, which displaces some of the aluminum atoms in the crystal lattice of aluminum oxide, that constitutes the mineral corundum. Burma and Sri Lanka rubies contain only chromium as the color inducing agent, but the Thai rubies also contain iron in addition to chromium, which imparts a darker red color to the rubies with a brownish or purplish overtone.
The various shades of red color in rubies including the lighter shades such as pink color, are caused by different concentrations of chromium in the corundum. Higher the concentration of chromium darker the shade of red. Lower the concentration of chromium lighter the shade of red (pink).
As Sunil rightly pointed out all shades/hues of red color in corundum including pink were known as rubies prior to the onset of 20th-century. However, it appears that the terms "Red Ruby" and "Pink Ruby" had been used in the past to differentiate between the two. An extract from an article published by J.F. Stewart in the "Ceylon Observer" on June 11,1855, titled "Gems and Gem Searching in Saffaragam" in Sri Lanka, depicts the use of the term "Pink ruby" in the 19th-century.

"The Pink-ruby is a beautiful stone and seldom met with. It is by some prized equally with the ruby. It is of a light ruby colour with a strong dash of pink in it. This is likewise rarely found without blemish. It sells well when defectless, both among Europeans and Asiatics."

The following comment by Harry Emmanuel in 1873, shows the range of hues of red color that were considered as rubies :-

"The colour of the ruby varies from the lightest rose-tint to the deepest carmine. Those too dark or too light are not esteemed"

One of the first references to "Pink Sapphire" can be seen in the following comment by G.F.Herbert Smith, mineralogist and gemmologist, and former "Keeper of Minerals" and Secretary of the British Museum, in his book - Gemstones and Their Distinctive Characters - published in 1912 :-

"The tint of the red stones varies considerably in depth; jewelers term them, when pale, pink sapphires, but, of course, no sharp distinction can be drawn between them and rubies."

The ambiguities and lack of a sharp distinction between rubies and pink sapphires expressed by Herbert Smith in 1912, persists to this day. The controversy still continues.
Richard W.Hughes, the foremost authority on rubies and sapphires in the world and author of the book "Ruby and Sapphire" comments on the on-going controversy as follows :-

We don’t have this problem with blue sapphires; light or deep blue, they are still blue sapphires. So why not label all red corundum ruby, regardless of depth or intensity, just as was done prior to the 20th century? This would eliminate the above problem.
In 1989, the International Colored Gemstone Association (ICA) adopted just such nomenclature. Unfortunately, the powerful American market continues to use the term pink sapphire, leading producing countries both by the nose and all of us into needless problems.

In the United States a minimum color saturation must be met for a gemstone to be classified as a Ruby, otherwise the stone will be called a pink sapphire. However, what this minimum color saturation is, has not been clearly defined, and the ambiguity still persists.

To give a start to this thread let us first include the impressive Ceylon/Sri Lanka blue sapphire, cushion-cut, with a saturated even blue color and extraordinary clarity, weighing 102.61 carats, the centerpiece of an "Impressive and Rare Sapphire and Diamond Necklace" that appeared at the Sotheby's Hong Kong Magnificent Jewels & Jadeite Spring Sale, held on April 7, 2014, and sold for US$ 4,203,118, the highest price achieved by a Sri Lanka blue sapphire at an auction, and the 3rd-highest price achieved by blue sapphire single stone at an auction.

Thanks Anitap and Sunil for your updates. We are mainly dependent on your updates to carry on this discussion. In the context of the increase in demand for natural blue sapphires around the world, I think it is worthwhile carrying on this discussion, so that our readers would be well informed of the market trends for high-quality natural blue sapphires, arising from different sources. I really do not know how we missed such a significant Burma/Mogok sapphire weighing 114.73 carats that sold for US$ 7,137,821 at the Sotheby's Geneva Magnificent Jewels Sale held in November 2013. As you have rightly pointed out this Burma sapphire had broken the world record for a sapphire whole stone in November 2013, but in terms of price-per-carat of US$ 62,214 it is not significant, but still falls within the range for Burma sapphires. In any case this Burma Sapphire can now claim to be the most expensive Burma sapphire ever sold at an auction.

The Sri Lanka sapphire highlighted by AnitaP with a weight of 102.61 carats that sold for US$ 4,203,118 is also significant in terms of its whole stone price, now occupying the 3rd-position in the list of Blue sapphires registering highest whole stone prices, but insignificant in terms of price-per-carat. The ppc of US$ 40,962, though not significant when compared to Kashmir blue sapphires is one of the highest ppc recorded for a Sri Lanka sapphire at an auction. Apart from that this blue sapphire is the most expensive Sri Lanka blue sapphire ever sold at an auction.

The revised list of blue sapphires that recorded the highest whole stone prices at public auctions is given below :-

A study of the two lists above clearly shows that there is a definite grading in prices of blue sapphires based on origin - Kashmir, Burma, Ceylon (Sri Lanka) - as suggested by Richard Hughes in his book "Ruby & Sapphire". This grading is seen both for the whole stone prices and price-per-carat values. The first, second and third most expensive blue sapphires in the world are the Richelieu Kashmir sapphires, the 114.73-carat Burma blue sapphire and the 102.61-carat Sri Lanka blue sapphire that sold for USD 8,358,520, USD 7,137,821 and USD 4,203,118 respectively.
The price-per-carat list also shows that the ppc of sapphires 1 to 11 varying from USD 175,821 to USD 64,460 all belong to Kashmir blue sapphires. PPC of 12 and 13 equal to USD 62,214 and USD 48,871 belong to Burma sapphires and PPC of 14 equal to USD 40,962 belongs to a Sri Lanka Sapphire.