The Lesedi La Rona, a 1,109-carat, tennis ball-sized diamond in Botswana, failed to sell for over US$70 million at Sotheby's auction held in London, says reports.

At the auction, the Sotheby's auctioneer failed to persuade bidders to go above US$61 million for the jewel, which was discovered in 2015 by the Lucara Diamond Corp, says reports. The industry players have said that gem market may have reached a tipping point and demand for large rare stones might just be saturated. Besides, market volatility due to Brexit may have added to it.

Lesedi La Rona means "our light" in Botswana's Tswana language. It could be cut into smaller gems for jewellery or left whole in a private collection.

"Though widely admired in the months preceding this evening's auction, and despite having seen bidding in the salesroom, the Lesedi la Rona failed to reach its reserve price and consequently did not find a buyer tonight," Sotheby's said in a later statement.

The report further adds that the precious stones have been fetching ever-higher prices at auction lately, as the world's ultra-rich invest in hard assets as a safeguard against stock market volatility.

The record for the biggest diamond in the world is still held by the "Cullinan Diamond", a legendary gem found in South Africa in 1905 boasting 3,016.75 carats.