Sapphire blue gemstone

Blue sapphire, a variety of the mineral corundum, is one of the world's most valuable gemstones, prized for its intense color and durability.

About this subject

Blue sapphire belongs to the corundum family, the same mineral that forms ruby. Its characteristic blue color comes from the presence of titanium and iron in its crystal structure. The most famous deposits are in Kashmir (India), Myanmar, Sri Lanka, and Madagascar. The quality of a sapphire is determined by hue, saturation, and clarity, with intense velvety blue being the most desirable.

Historically, blue sapphire symbolizes nobility, wisdom, and divine protection. Kings and clergy wore them in jewelry and regalia. Princess Diana's engagement ring, now worn by Kate Middleton, is a 12-carat blue sapphire, further popularizing the gem. In many cultures, sapphire is believed to bring peace and honesty.

Technically, sapphire is extremely hard, 9 on the Mohs scale, second only to diamond. This makes it ideal for daily wear in jewelry. Heat treatment is common to enhance color, but untreated natural sapphires are rarer and more valuable. Sapphire also has technological applications, such as in watch crystals and electronic components.

Fun fact: the largest sapphire ever found is the "Star of India," weighing 563 carats, displayed at the American Museum of Natural History. Sapphires with star-like inclusions (asterism) are especially prized. The price of a high-quality blue sapphire can exceed US$ 100,000 per carat.

Frequently Asked Questions

What determines the blue color of a sapphire?

The presence of titanium and iron in the corundum crystal structure absorbs yellow and orange light, resulting in the blue color. The intensity and shade of blue vary with the proportions of these elements.

What is the difference between natural and treated sapphire?

Natural sapphires undergo no processes beyond cutting and polishing. Heat-treated sapphires are heated in a lab to enhance color and clarity. Natural ones are rarer and more valuable.

Where are the best blue sapphires found?

The most renowned deposits are in Kashmir (India), Myanmar, Sri Lanka, and Madagascar. Kashmir sapphire is famous for its unique velvety blue, but the mines are now mostly depleted.