The Star of Adam

The Star of Adam is an oval-shaped blue star sapphire, currently the largest star sapphire in the world. It weighs 1,404.49 carats (280.898 g; 9.9084 oz), and its estimated cost is at least US$ 100 million. However, its expected worth at auction is up to US$ 175 million. Prior to its discovery, the Black Star of Queensland, weighing 733 carats (146.6 g), was the largest star sapphire gem in the world. The blue-colored gemstone has a six-pointed star-shaped reflection or distinctive mark in the center.

This very large star sapphire was discovered in Ratnapura (known by the nickname "City of Gems"), in southern Sri Lanka, in August 2015. It was named "The Star of Adam" by the current owner, as a reference to Muslim beliefs that Adam arrived in Sri Lanka and lived on Adam's Peak after leaving the Garden of Eden.

The owner of the gem, preferring anonymity, told the BBC World Service's Newsday radio programme that "The moment I saw it, I decided to buy", and added "this was not a piece of jewellery but an exhibition piece".

The blue star sapphire's weight of 1,404.49 carats (280.898 g; 9.9084 oz) was certified by the Gemmological Institute of Colombo; the institute said that it had never certified a gemstone larger than "The Star of Adam". A leading gem and jewelry dealer in the country confirmed to the BBC that it was the largest blue star sapphire in the world. In an interview to BBC Earth, Simon Redfern, mineral scientist from the University of Cambridge, said "the stone could have formed within the granite rocks of Sri Lanka's highlands. It was able to grow so big because of constant but slow change in temperatures and pressures within the rocks for millions of years".

Later, the gemstone was valued at over $300 million.