Invest knowledgeably - The sapphire, sumptuous and accessible | EN

Like the ruby, the sapphire is a very hard, natural crystallized form of corundum (Al2 O3). It has been well known since the dawn of time, and it is much more plentiful than its imperial companion in mineralogical classification because of the multiple colour combinations of iron and titanium which are found in the upper layers of the earth's crust, where sapphires were formed.
The Chaldeans called it the “sampir", the Greeks the “sappheiros", the Latins the "saphirus", the Arabs the "safir" and the Hebrews the "sappir" (the most beautiful thing).

The sapphire belongs to the rhombohedral crystalline system. It is found that the same level as the ruby, just behind the diamond - the hardest of all minerals - on the Mohs scale (hardness - 9).
 
Its density lies between 3.96 and 4.10, and the refraction index is between 1.76 and 1.77. It must be pointed out that precious corundum is located in cipolins, basalts, pegmatites and the alluvium, which derives from them.
 
The three most beautiful colours
The most sought after gems are those, which are very limpid, and also have a deep luminous tint. The colours are extremely varied, and they range from white to black, through pink, yellow, mauve, and green, acquiring the names of "pink sapphire”, “yellow sapphire” etc.
 
It is the integrations of chrome, iron and titanium, which have exerted a dominant over the particular colour of the stones. Even though enthusiasts might search eagerly for those types of sapphire because they are of undeniable value, it is very certain that the most beautiful belong to the blue category and, for purposes of investment, the following selection will be considered. Cornflower blue. This is the most sought after sapphire, because it has a deep, bright, velvety, soft blue tone ennobled still further by a soupcon of royal purple. A large number of these most beautiful stones, also known as "cashmere blue" used to come from this region. Now the mines are practically exhausted, and it is necessary now to turn to the deposits in Thailand, Sri Lanka and Cambodia, in order to find gems equivalent in quality and purity. Royal blue is another remarkable tone. What is striking in this case, is the depth of this pure tint, something like the clear waters of seemingly bottomless mountain lakes. Navy blue is yet a third shade of blue, which is interesting from all points of view in the tone pallet.
 
A limited production
To be considered, with its exceptional colouring, a sapphire should not have "windows", that is to say when the stone is looked at from all angles that there should not seem to be holes in the depth of the tint the verberation of which in the light will still remain warm and velvety.
 
If one speaks of the "cashmere blues", as if they were memories since the deposits no longer contain jewels, those of Thailand turn from rich blue to blue-black, whereas the gems from Sri Lanka belong to the category of "kingfisher blues" and very light blues. It is also as a mere memory that Burmese sapphires will be mentioned, because the mines, just as the precious-stones markets, have been nationalized, and no longer enjoy their reputation of yesteryear. In Cambodia, the famous Pailin mines where closed because of the unstable political situation, but now new stones are coming from this region.
 
It is an established fact that the sources of supply are restricted, and that is the reason why sapphires are holding their price on the world markets. There is of course Australia which at present is making an extra-special effort to produce stones from its mining centres, but these gems have a greenish, dark blue colour or a sombre, dull blue which robs them of any real value by comparison, thereby placing them at a much lower point on the prices scale than the sumptuous sapphires sought after by investors.
 
Certain sapphires, as in the case of rubies, also reveal asterism. They are then cabochon shaped. Without matching the upward tendencies on the market of other stones, sapphires nevertheless increased more or less 30% in a year, and all the signs are that they will not be long in making up their present leeway. With regard to commercial quality, a price oscillating between 120 and 700 dollars per carat must be considered. With regard to large stones of incomparable water, the price then stands at 5,000 to 15,000 dollars.
 
Lets look at Auctions:
April 2012 Sotheby’s Hong Kong Sapphire Kashmir 8,65 ct sold at 98.573 us $ per ct.
December 2011 Sotheby’s New York Sapphire Kashmir, 16,40 sold at 97.226 $/per ct
November 2011 Christie’s Hong Kong Sapphire Kashmir 26,41 sold at 145.347 $ per ct
May 2011 Christie’s Hong Kong Sapphire Kashmir 13,47 sold at 145.340 $ per ct
May 2011 Christie’s Hong Kong Sapphire Kashmir 14,84 sold at 145.340 $ per ct