(IDEX Online) - Plans by Botswana Diamonds to buy the loss-making Ghaghoo mine have collapsed, after it failed to secure a joint venture partner.The Irish explorer had a a non-binding agreement with owners Gem Diamonds, dependent on it finding a partner by 10 May. But it says there's still a possibility it will resurrect the agreement.The mine, about 300 km northwest of the capital Gaborone, has an inferred resource of 28.78m tonnes with an average grade of 17.52 cpht and an average diamond value of $239/ct.Botswana Diamonds said in a statement "Gem Diamonds have indicated its willingness to re-engage on substantially the same terms as the agreement if Botswana Diamonds and a partner can finalise an agreement and, accordingly, Botswana Diamonds is continuing its discussions with potential joint venture partners."Gem has been trying to sell the mine (pictured), which it describes as a "non-core asset" since it was mothballed in 2017. A 2019 deal with Botswana-based Pro Civil fell through.Another potential deal, with the UK-based mining and resource development company Vast Resources, was announced last August, but Vast pulled out in February.