Although blue sapphire can be sourced in many locations across the world, historically the three most important sources are Kashmir, Myanmar and Sri Lanka. These countries produce the best quality blue sapphire. Kashmir sapphire is widely regarded as the finest-quality blue sapphire and possesses an exquisite, rare beauty with a velvet soft cornflower blue colouring which makes it so desirable.
‘Kashmir’ is often a term used to describe the colour of the stone that has a violetish to pure blue hue, with moderately strong to vivid saturation. Usually, inclusions can reduce the value of a stone if they affect its durability. However, some of the most expensive Kashmir sapphires include tiny inclusions that give the stone a velvety lustre. This clarity characteristic occurs when light scatters over the fine rutile needles without affecting the transparency of the gemstone.
It is common in Kashmir sapphires for the colour to strongly concentrate close to the surface of the crystal; this characteristic is called colour zoning. Cutters will make sure that the sapphire is cut to accommodate the colour zoning of the rough, making sure that when the stone is viewed face up it displays entirely blue.
Kashmir's famous reputation rests on only a small mining period of seven years in the late nineteenth century. The Kashmir mines are situated high up in the constantly snow covered Himalayas, posing many challenges to the workers who operate the mines.
A landslide in 1881 caused a pocket of gem-quality blue sapphires to be discovered. The deposit was situated just above the village of Sunjam at 14,760 ft in the Zanskar mountain range of the Himalayas. The blue sapphires were initially simply removed from the decomposed rock. Over time the mining continued at random intervals and due to the inhospitable climates the mine produced less and less rough. Only small amounts of gems have been produced from the area since Kashmir mining depleted in 1887. Now there are only very small amounts of Kashmir sapphires in circulation throughout the world, adding to their rarity and value.