Black Star of Queensland is a 733-carat (146.6 g) black sapphire, and the world's largest gem quality star sapphire. It was discovered in Australia in the 1930s. The gem has been involved in several ownership disputes.
The Black Star of Queensland was on display during the 1960s at the Smithsonian as part of a display with the Hope Diamond. From 2 June through 2 December 2007, it was on display at the Royal Ontario Museum. The sapphire is now owned by an unknown private party and is not believed to be on public display.