Star Sapphire - comics - was created in 1976.

What is the value of a 27.2 natural blue sapphire?

A Star sapphire has an asterism, a star-like central feature- made this way by Nature. The regular Sapphire may or may not have this feature. Sapphires rate 9 on the Mohs scale of hardness, below Diamond but on the same plane as Ruby, and something familiar from the shop class- Carborundum.

The Black Star of Queensland.

An artificial Blue star sapphire. These were engineered by Union Carbide- Linde division ( pronounced Lindy- like the Airman). They are expensive but less so than real diamonds.