[1/2] A worker attends to machinery at a smelter plant at Anglo American Platinum's Unki mine in Shurugwi, Zimbabwe, May 16, 2019.
The southern African country has struggled to capitalise on its significant mineral reserves and a resource boom due to policy uncertainty, a lack of ancillary industries to support mining, currency volatility and electricity shortages.
The cash component of the royalties would be made up of 40% Zimbabwean dollars and 10% in foreign currency, according to the notice.
Zimbabwe's royalty rates range between 5% for gold and platinum group metals and 10% for diamonds.
The Zimbabwe Chamber of Mines, which represents major mining companies, has said it is not worried about the new royalty policy because it does not amount to an increase in existing royalty rates.