[6] This very large star sapphire was discovered in Ratnapura (known by the nickname "City of Gems"), in southern Sri Lanka, in August 2015.
[9]: 374–375 A leading gem and jewelry dealer in the country confirmed to the BBC that it was the largest blue star sapphire in the world.
[2] 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".
[12] Bangkok-based Lotus Gemology maintains an updated listing of world auction records of ruby, sapphire and spinel.