Black Opal of this quality, to put it mildly, is ‘exceptionally rare’. This is what all opal miners dream of finding. black opal of this quality in a stone as large as this is simply unbelievable. This gem was found many years ago and is currently for sale BUT you will need a wheelbarrow full of money. It is probably the most beautiful gemstone I have ever held. It weighs in at an astonishing 306 carats!