By 3000 bc gold rings were used as a method of payment. . By ad 100, up to 40,000 slaves were employed in gold mining in Spain. .. its application and compelled the use of carefully designed equipment to ensure against contamination.
Gold extraction refers to the processes required to extract gold from its ores. This may require a .. Gold Field Mineral Services (GFMS) (goldavenue ) & I Podleska and T Green goldavenue Archived 2002 04 01 at the Wayback Machine.