What's With Kashmir Sapphire?

28.18ct Kashmir sapphire sold at Sotheby's for $5.1M in April, 2014

CELEBRITIES LOVE SAPPHIRE
Sapphires are a beloved precious stone. Britain's queen-in-waiting Kate's engagement ring is a sapphire and diamond creation. And it's not even the most coveted sapphire type, since those from Kashmir are considered the most valuable and rarest in the world.

PROVENANCE MATTERS
Kate's ring is a valuable one of course, owing to its quality and provenance. Prince Charles paid about $45,000 US for the ultra blue sparkler in 1981. Princess Diana’s dazzling sapphire engagement ring now graces the finger of daughter-in-law Duchess Kate of Cambridge, and is worth about $480,000 US today, more than 10 times of its original purchase price.

WHAT, WHY & WHERE OF KASHMIR
But all things being equal, serious collectors go long for Kashmir sapphires which are all but mined out today. They originated in super high altitudes at mines deep within remotely accessed Jammu and Kashmir region at the northernmost tip of India.

Red area show Jammu and Kashmir atop India

But the difficult recovery is not all that drives their value. Geology plays a huge roll in a gemstone's appearance. What they are composed of, and the terrain which produced gemstones all contribute to their individual look. In the case of Kashmiri sapphires, collectors are enamored with their rich deep (but not too dark) blue and an almost indescribable velvety appearance, according to some. This soft and sumptuous appeal is the result of microscopic rutile (another mineral) inclusions. The inclusions appear like tiny threads or strands, and are referred to as silk.

Micro-image of rutile silk in sapphire Courtesy GIA

While you may not see it with the un-aided eye, this tell-tale trait keeps Kashmir sapphire in the most-wanted short list of world class gemstone collectors everywhere.