(IDEX Online) - A 21.86-carat natural pink diamond from the Kao mine, in Lesotho, is be sold next month in Antwerp.Kao is one of the few sources of pink diamonds following the closure last year of Rio Tinto's iconic Argyle mine, in Australia, which provided 90 per cent of the world's pinks.The rough stone (pictured), discovered on 18 May and named The Pink Palesa, will be offered for sale by the Bonas Group, in Antwerp, with online bidding closing on 23 July. Namakwa owns and operates the Kao mine through its subsidiary, Storm Mountain Diamonds (SMD).The kimberlite pipe at Kao is the largest in Lesotho and the fourth largest in Southern Africa. SMD is jointly owned by Namakwa Diamonds Limited and the Lesotho Government. In recent years Kao has yielded the 25.97-ct Pink Dawn (2021) the 36.06-ct Pink Storm (sold in 2014) the 3.06-ct Purple Princess (2017) and the 29.59-ct Rose of Kao (2018).