The company, South Africa's largest gold producer, has run up losses of about 1.6 billion rand ($114 million) and about 110,000 ounces of missed gold output because of the labour action.
The International Tin Association and the Responsible Business Alliance want to join forces to tackle minerals sourcing challenges from higher risk areas.
Botswana's state-run Okavango Diamond Company has unveiled what is believed to be the largest blue diamond ever discovered in the southern African country.