Priceless 8 carat pink diamond goes on show

Most Argyle pink diamonds are less than a quarter of a carat. Photo / Thinkstock

They say diamonds are a girl's best friend, so which girl wouldn't want the Argyle Pink Jubilee?

The 8.01 carat sparkler - Australia's largest pink diamond and a unique and priceless treasure - has gone on permanent display in Melbourne.

"It's glamorous and pretentious and billions of years old ... everything you want in a diamond," says a giddy Michael Neuman, co-director of jeweller Mondial Pink Diamond Atelier.

After being unearthed in Rio Tinto's Argyle diamond mine in Western Australia last August, the diamond was originally destined for sale at an annual invitation-only tender.

But it was only capable of being partially cut and polished and was cut down to 8.01 carats, weighing 1.602 grams.

About 75 per cent of Argyle pink diamonds are less than a quarter of a carat and can fetch roughly NZ$130,000 to NZ$260,000 each.

The diamond is the largest found in the 26-year operation at the Argyle mine, which produces virtually the entire supply of the world's pink diamonds. Pink diamonds are already considered a rare commodity, comprising less than 0.03 per cent of global diamond production.

It's the Argyle Pink Jubilee's size as well as its colour that makes it so much more exceptional.

"We will find a handful of pink diamonds every year and of that handful, five or six will be more than one carat," Rio Tinto Australia managing director David Peever said today as the jubilee went on displayed in Melbourne.

But there's no putting a pricetag on the pink jubilee. It's simply priceless, Mr Peever says.

Rio Tinto has donated the diamond to the Melbourne Museum, where it will remain everybody's best friend.

-AAP