The huge “Star of Adam” was located in Sri Lanka, and is believed to be the largest sapphire ever found. It weighs 1,404 carats, which is about 280g. But how could it grow so large?
Sapphire is a bright blue gem mineral and a type of corundum (aluminium oxide). It is very hard, which is important in understanding its location in countries like Sri Lanka.
The Star of Adam sapphire is a beautiful example of a “star sapphire”. It seems to have a 6 point star inside the stone. This is due to light reflection from small crystals trapped within the sapphire as it grew.
The gems are found in old river sediments. Due to the hardness the sapphires survived as big pebbles and crystals.
The Star of Adam would likely have been formed inside rocks and granites in the highlands. The have been dated as close to 2 billion years old.
The temperature and pressure would have altered very gradually over many millions of years, which is how the sapphire was able to get so large.
The sapphire is privately owned.