Rio Tinto has unveiled its 2016 Argyle Pink Diamonds Tender collection at an exclusive preview event in Copenhagen.
Western Australia’s Argyle diamond mine, operated by Rio Tinto, is the world’s largest diamond producer by volume and the only known significant source of pink and red diamonds.
Each year, a collection of the best diamonds recovered at Argyle is offered for sale in an invitation-only event known as the Argyle Pink Diamond Tender.
This year’s collection has been named the ‘Chroma Collection’ and comprises 57 pink diamonds, two violet diamonds and four red diamonds.
Rio Tinto says the centrepiece of the collection is the ‘Argyle Violet’, a 2.83-carat oval-shaped violet diamond that made headlines around the world when it was first discovered in 2015. The Argyle Violet is expected to fetch more than $4 million at the sale later this year and is the largest violet diamond ever recovered at the site.
The Argyle diamond mine is located in the far northeast of Western Australia in the east Kimberley region and has been in operation since 1983.
For most of its existence Argyle has been an open pit style mine, but from 2015 onwards Rio Tinto has been operating an underground mine at the site. It was from this underground mine that this year’s collection was sourced.
The Argyle mine uses two large underground crushers and conveyor belts to transport ore from deep below ground to the surface.
From there, the ore is sorted using a two-stage heavy-medium cyclone to separate denser, diamond-containing ore from waste material. This denser material is then analysed by custom X-ray technology to identify small diamonds.
Following the event in Copenhagen, the 2016 Argyle Pink Diamonds Tender will be showcased during viewing events in Hong Kong, New York and Perth before final bids close on October 12.