This is the biggest violet diamond Rio Tinto has ever found

This is the biggest violet diamond Rio Tinto has ever found

Image: Rio Tinto.

Rio Tinto (LON:RIO) unveiled Tuesday a rare 2.83-carat violet diamond, the largest of its kind ever found at Australia's remote Argyle mine, which could sell for more than $4 million.

The extremely rare diamond, known as The Argyle Violet, is 2.83 carats and has been polished in an oval shape.

The oval shaped rock, known as the Argyle Violet, will be the centrepiece of the 2016 Argyle Pink diamonds tender, the annual showcase of rarest diamonds unearthed from the mine.

The Argyle Violet, found in August last year, originally weighed 9.17 carats and had etchings, pits and crevices. The company says it took more than 80 hours of work to polish it down to what is now.

While the company did put a figure on the diamond’s worth, it is estimated the gem could attract offers anywhere from $1m to $2m a carat.

"Impossibly rare and limited by nature, the Argyle Violet will be highly sought after for its beauty, size and provenance," Rio Tinto Diamonds general manager of sales, Patrick Coppens, said in the statement.

This is the biggest violet diamond Rio Tinto has ever found

Image: Rio Tinto.

Coppens noted that violet diamonds are a very rare find. In fact, in its 32 years of operation, Argyle has produced only 12 carats of polished violet diamonds for its annual tender.

The mine, which generates more than 90% of the world's pink diamonds, has only produced one other significant violet-coloured rock weighing 1 carat or more. That diamond was discovered in 2008, so the Argyle Violet is " a complete fluke of nature," Josephine Archer from Argyle Pink Diamonds told Yahoo7 News.

The 2016 Argyle Pink diamonds tender will begin private trade viewings in June and travel to Copenhagen, Hong Kong and New York.