Sapphire blue gemstone

Blue sapphire is a variety of corundum, hardness 9 on the Mohs scale, widely valued in jewelry and a symbol of royalty.

About this subject

Blue sapphire is one of the world's most iconic gemstones, belonging to the corundum family, the same mineral as ruby. Its intense blue color is caused by the presence of iron and titanium in its crystal structure. With a hardness of 9 on the Mohs scale, it is second only to diamond, making it extremely durable for everyday wear in rings and other jewelry. Historically, blue sapphires have been associated with royalty and clergy, used in crowns and insignia of power. The famous engagement ring of Princess Diana, now worn by the Duchess of Cambridge, features a 12-carat blue sapphire surrounded by diamonds.

Major sources of blue sapphires include Kashmir, Myanmar (Burma), Sri Lanka, Australia, and Madagascar. Kashmir sapphires are considered the finest, with a unique velvety blue, but the mines are nearly depleted. Sri Lankan sapphires are known for their clarity and lighter tones, while Australian sapphires tend to be darker. Most sapphires on the market undergo heat treatment to improve color and clarity, a common and accepted practice.

A fascinating curiosity is the star sapphire, which exhibits an optical phenomenon called asterism, caused by needle-like rutile inclusions. When cut as a cabochon, it displays a six-rayed star that moves with the light. Besides blue, sapphires can be found in other colors such as pink, yellow, green, and orange, known as "fancy sapphires." Sapphire is the birthstone for September and symbolizes wisdom, virtue, and fidelity.

Frequently Asked Questions

What is the hardness of blue sapphire?

Blue sapphire has a hardness of 9 on the Mohs scale, second only to diamond. This makes it very resistant to scratches and suitable for everyday wear in jewelry.

Where are the best blue sapphires found?

Kashmir sapphires are considered the finest, with a velvety blue. Other major sources include Myanmar, Sri Lanka, Australia, and Madagascar.

What is a star sapphire?

It is a sapphire that exhibits asterism, a phenomenon where rutile needles form a six-rayed star when cut as a cabochon. It is highly prized by collectors.