It announced today it had struck a three-year renewable services agreement with cooperative Txapemba Canguba RL.
The latter has an 84 sq km concession for the semi-industrial exploitation of diamonds within the Luembe River basin - an area, which was a past alluvial diamond producer and well known for both alluvial and kimberlite diamonds.
Tango will be responsible for capital expenditures associated with alluvial mine design and buying equipment and will be the sole operator.
It says it will complete in the coming months a full geological assessment and plans to start alluvial diamond production as soon as practical.
Tango will receive 60% of the proceeds from the sale of produced stones, while all Tango's operational costs are deductible.
Angola has been actively encouraging foreign investment in its diamond sector under a new mining code introduced in 2011, which no longer includes the requirement for Angola to hold a majority interest in diamond mining projects.
Alrosa is the operator of the world's fourth-biggest diamond mine Catoca, some 220km southwest of the property and within the same geological setting (Lucapa Graben).
Tango Mining shares were uchanged in Toronto at C$0.035.