Gold

Some 15 million artisanal and small-scale miners scrape a living doing backbreaking work in harsh conditions to produce 200-300 tonnes of gold a year. In all, 100 million people worldwide depend on artisanal and small-scale mining for their survival.
Mining rights are generally given to large-scale industrial mining companies so small-scale miners are pushed into running informal, often illegal operations.  Conditions are hazardous and health and safety measures are inadequate, with real health risks posed from handling toxic mercury and cyanide. These miners are at the end of long and complex supply chains and have little option but to accept the price offered by traders, however low.  
http://www.fairtrade.org.uk/en/farmers-and-workers/gold