Of this, 250 carats were placed on tender in Johannesburg and sold with an average price of US$1,155 per carat.
It is planned for the other 62 carats to be exported to Dubai to be sold by ATC Enterprises DMCC.
As a comparison, in the month to March 20, 307.94 carats from 183 diamonds were produced and sold with an average price of US$875 per carat.
In the latest period, the top three highest value diamonds recovered include a 14.64-carat diamond which sold at US $5,019 per carat, a 6.35-carat diamond which sold at US$3,357 per carat and a 7.82-carat diamond which sold for US$3,377 per carat.
Diamond production from Oena since acquisition now totals 876 carats, of which 804 carats have been sold at an average price of US$1,290 per carat.
Oena covers a 4.8km wide strip along a 15km length of the Orange River in a well-established alluvial diamond-mining province known to produce high-quality and large-sized diamonds.
African Star Minerals , of which Tango has a stake, owns 100% of the property.
As well as the Oena interest, Tango, via South African subsidiaries, holds three thermal coal, metallurgical and processing plant, and engineering contracts that process 6.5 million tonnes of coal a year, with clientele that include Exxaro.