Of all the precious stones, corundums constitute the most important and richest family in terms of the variety of colors, crystal dimension, transparency, and elevated clarity of the most beautiful samples, known as “gem quality”.

Corundums in all shades of red are known as rubies, while the sapphire denomination, preceded by the specific color (i.e. yellow sapphire), is given to all those which are not red. These vary in color from yellow to orange, purple, and green, with black and white samples; however, the most soughtafter color has always been blue. References to the blue sapphire are found in the most ancient civilizations: in Sanskrit it was called sauriratna, sappheiros in Greek, shamir in Hebrew, and safir in Arabic, although the exact origin of the name is unknown.

In various cultures, the blue sapphire, emblem of the sky and a symbol of the divine in many religious traditions, has been associated with harmony, faithfulness, and love, and has always held a place of honor among gemstone enthusiasts; Marco Polo recounted selling sapphires coming from Ceylon (currently Sri Lanka) to the Grand Khan at double the price. The island of Ceylon was the first source of sapphires and is still the main producer, though production is declining. In general, Ceylon sapphires are characterized by an “overtone of gray”, a slight gray gradation, while in the best quality they recall the color of the cornflower, an extremely brilliant, intense light-blue.

The discovery of sapphire mines in Burma brought some gems of exceptional quality to the market, especially from the mines of Mogok, with a highly sought-after blue shade known commercially as “royal blue”. Very few
samples that exhibit high color saturation and homogeneity and depth of tone are worthy of this denomination and their market prices always reach very high figures.

An important year in the history of blue sapphire extraction is 1881, the year in which a land-slide in a remote region of Kashmir, in the north-west Himalayas revealed a rock rich with extraordinarily beautiful sapphires.
Word spread quickly and the area, cold and impervious, became overrun with prospectors and adventurers until the Maharajah of Kashmir sent his troops to possess it. In the five years that followed, the territory, under the direct control of the Maharajah, was intensely exploited and these sapphire deposits yielded notable gems before gradually becoming exhausted. At the beginning of the 1930’s, all of the mines were depleted.
To sapphire lovers, the name Kashmir immediately evokes an image of a velvety, intense, deep, and unique color – the most sought-after and appreciated of all sapphires.

The prices for carat for these gems are among the highest on the market, both because of their rarity and of their unique soft, misty color, which comes from the homogeneous diffusion of light due to subtle inclusions within the gem. Kashmir sapphires do not present shades of gray, green, or violet; they are exclusively of an intense blue which remains unchanged when observed in sunlight, fluorescent and incandescent light.
Other sapphire production mines exist today, principally in Thailand, which produce gems with a lovely blue tone, but less intense in color than the Burmese, while Australian sapphires, easily recognizable by their characteristic blackish tone, are generally less valuable. There are also Montana sapphires, not always uniform in tone, which are very much appreciated by the American public, and Cambodian gems which are of good color and intensity but tend towards green, and also African sapphires as well, but none of the newly discovered mines has yet produced gems capable of matching the unsurpassed beauty of the Kashmir stones.

Today, Kashmir sapphires may be found only in antique jewels, from which they are sometimes removed in order to be re-cut and set in contemporary jewels.

The cushion-cut Kashmir sapphire of approximately two carats which will be auctioned by Bolaffi on 3 October with a starting price of 15,000 euros maintains its original 1920’s setting in platinum and diamonds. The stone has not undergone any treatment to improve the color, which makes it more valuable. Treatments to improve the color and purity through heat have been known for ages and are applied to the great majority of gems.

This color modification is quite stable and, depending on the intensity of the process, the inclusions that determine the origin of the gem may or may not still be visible. Precious stones that have not undergone heating are therefore very rare and it is advisable for them to be accompanied by a gemological certificate issued by an accredited institution, as SSEF in Basel.