Sapphire: The Starry-Eyed Gemstone

You might’ve thought that you have heard enough facts about blue sapphires since they’re so popular today, but here’s one that might take you by surprise!

There are some sapphires known as “star sapphires” that exhibit a unique phenomenon called asterism, where six-pointed star patterns appear on the surface of the stone. This is caused by tiny inclusions of rutile, which is a black or reddish-brown mineral consisting of titanium dioxide, that shows up as needle-like crystals within the sapphire.