A 15.81-carat diamond could fetch up to $38 million when it goes on sale in Hong Kong next week.

The Sakura -- named after the Japanese word for cherry blossom, due to its vibrant hue -- is the largest purple-pink "flawless" diamond ever to appear at auction.

 The rare stone is set on a simple platinum ring and has been classified as internally flawless, meaning that any blemishes are only visible under close magnification. It has also been classed as being "fancy vivid," a measure of intense color achieved by only 4% of pink diamonds, according to a press release from Christie's, the auction house organizing the sale.

Chairman of Christie's jewelry department, Vickie Sek, said in a phone interview that the stone is "exactly" the shade of a sakura flower. She added that it is "very rare" for pink diamonds to be classified as internally flawless, as they usually contain "a lot of graining."

At nearly eighty times that size, the Sakura may also break the record for the most expensive purple-pink diamond to sell at auction. The current record is held by "The Spirit of the Rose," a 14.8 carat diamond fetched almost $27 million at Sotheby's last year.

Pink diamonds come in various different shades, with stones like the Sakura notable for their purple undertones. While Sek said that "there's no rule saying (whether purely) pink diamonds or purple-pink diamonds are rarer," the former are responsible for even bigger sums at auction.

In 2017, a 59.6-carat pink diamond sold for a record $71.2 million at Sotheby's Hong Kong. The diamond, which was purchased by Hong Kong jewelers Chow Tai Fook and renamed "CTF Pink Star," remains the most expensive polished diamond of any color to sell at auction.

Despite the large sums expected at next week's auction, the coronavirus pandemic has affected global jewelry markets in the past year. According to research by Bain & Co, revenue from diamond sales dropped globally by 15% in 2020, while in the US, jewelry sales plummeted by 40% in the year's second quarter.