The gemstone weighs about 510 kilograms, that is, two and a half million carats. Its cost is about $100 million.
In Sri Lanka, the world's largest star sapphire stone was accidentally discovered by local residents in the backyard of their house. This is reported by the BBC.
The stone was discovered by workers while digging a well in the Ratnapura area.
Experts have already estimated its value and note that up to $100 million will be given for a pale blue stone on the international market.
Specialists from the National Office of Sri Lanka for Precious Stones worked with the find for more than a year, until it was completely cleaned.