Sri Lanka company prepares to sell massive blue gemstone

COLOMBO, Sri Lanka (AP) — A gem company in Sri Lanka has unveiled a rare and massive gemstone weighing 683 pounds (310 kilograms) that has been certified as one of the biggest corundums ever found in the country. Sri Lanka’s National Gem and Jewelry Authority says it has done a series of gemological tests on five samples taken from the rock and certified it as a “rare” specimen. Sri Lanka and especially its southwestern city of Ratnapura, or the Gem City in the local language, has been known for centuries for mining gems and precious stones.