ECONOMYNEXT – Sri Lanka’s largest ever recorded corundum, a family of gemstones to which includes sapphires, rubies and geuda, weighing 310 kilograms had been discovered from a mine in Balangoda, officials said.
“This is the largest single corundum stone recorded in Sri Lanka,” Thilak Weerasinghe, Chairman of Sri Lanka’s Gem and Jewelry Authority said.
“This is not an aggregate. It is a single stone. As far as we know it could be the largest recorded corundum in the world.”
Sri Lanka had earlier found a cluster of stones weighing over 500 kilograms.
“Corundum which is in the family of the saphhire is found in Sri Lanka and also Madascar,” Weerasinge said.
“Usually in Madagascar small pebbles are found. It is here that we find big ones.”
The stone had been dug from Balangoda, an area known for gems.
“We hope to have an online auction,” Chamila Suranga, Director of GIR Lanka, the company that owns the stone said.
“We are targeting museums and high net worth individuals in the Middle East and some other countries.”
Corundum, which is a form of Aluminum Oxide (Al203), with transitional metal impurities giving colours like blue or red. Geuda is opaque while blue sapphires are clear.
The stone which is opaque as in standard geuda type corundum, has patches of blue visible.
“If we cut it open we may find more clear areas inside, like the seeds of a jackfruit,” Weerasinghe said.
“But we need to examine it more.”
Corundum is formed when molten magma is forced out of the earth core and it coolls. Magma is usually about 3,500 centigrade.
“Corundum begins to form when magma cools to about 2,200 centigrade,” Weerasinghe said.
“We find corundum in the geological formations of Rakwana and surroundings. In Sri Lanka gems are found in secondary deposits. They have been washed away and deposited. The heavier stones gets deposited in the bottom of a waterway.”
Weerasinghe says he cannot personally give a value for the stone.
“It is difficult for me to personally to put a value on this,” he said. “But in an auction its value will go up based on the rarity.”
Already an offer in excess of a million dollars had come from prospective Middle Eastern buyer officials said, but the owners think it is worth multiples of that. (Colombo/Dec11/2021)