Famous Gems: the Halley's Comet Opal
Holding the Guinness Book of Records title as the largest uncut black opal, this gem is out of this world.
This beautiful giant holds the Guinness Book of Records title as the largest uncut black opal. Found in the area of Lightning Ridge, Australia, it was named after the famous comet that made its appearance around the time of the find. The opal weighs 1982.5 carats.