A sapphire is a precious gemstone known for its brilliant blue color, though sapphires can also be pink, yellow, green, or even colorless. The most prized sapphires have a deep, vivid blue that seems to glow from within. These gems form deep underground over millions of years when intense heat and pressure transform minerals containing aluminum and oxygen into crystalline structures. Tiny amounts of iron and titanium create that famous blue color.

Sapphires rank just below diamonds in hardness, making them extremely durable. This toughness, combined with their beauty, makes sapphires popular for jewelry that gets worn every day, like engagement rings. The British Crown Jewels include several enormous sapphires, and many royal families treasure sapphire collections passed down through generations.

For thousands of years, people believed sapphires had special properties: medieval kings thought sapphires protected them from harm and envy, while ancient Persian rulers believed the sky was blue because it reflected a giant sapphire holding up Earth.

Today, most sapphires come from mines in Sri Lanka, Madagascar, Australia, and Myanmar. The rarest and most valuable sapphires show a color described as “cornflower blue” and may cost thousands of dollars per carat.