A rare diamond up for auction at Sotheby’s in July can be purchased using cryptocurrencies, the auction house has announced.

Expected to reach up to $15 million, Sotheby’s has stated this is the first time a diamond of this size has been put up for public purchase using crypto, Reuters reports.

No other physical object of this value has ever before been available for sale with crypto, the auction house went on to say.

The 101.38-carat pear shaped flawless diamond, named ‘The Key 10138’, is only one in 10 diamonds of over 100 carats to be auctioned, with only two being pear-shaped.

The diamond has a $10 million - $15 million pre-sale estimate, and will be sold in Hong Kong on 9 July.

Bitcoin and Ether, the world’s two largest cryptocurrencies by market cap, as well as traditional fiat money, will be accepted as payment.

Patti Wong, chairman of Sotheby's Asia, said in a statement: “This is a truly symbolic moment. The most ancient and emblematic denominator of value can now, for the first time, be purchased using humanity’s newest universal currency.”

It’s been a year of volatility for cryptocurrencies, with record growth and plummeting prices.

Last week the National Republican Congressional Committee in the U.S. announced it will accept crypto donations; whilst earlier this month El Salvador became the first country to adopt Bitcoin as legal tender.

In May, Sotheby’s sold a Banksy for $12.9 million, the first time a piece of physical artwork was purchased with cryptocurrency at a major auction house.

The name of the diamond - Key 10138 - is designed to convey the essential role that keys occupy in the crypto world.