President John Magufuli also directed the central bank to buy the precious stone to boost reserves — the latest twist in a spat with mining firms over alleged tax evasion.
Initiative seeks contributing to global efforts in preventing the use of child and forced labour in the mining supply chain, and to providing information needed to demonstrate the responsible sourcing of minerals and metals.
Draft bill gives government first option to buy unusually large diamonds found in the country's mines, such as the world's second-biggest 1,109 carat diamond discovered by Lucara two years ago.