An international team of scientists have found that the mineral pyrite, often called fool’s gold because of being similar to gold but not as worthy, actually contains real gold in more ways than previously expected. The researchers claim that the discovery can help gold miners to extract gold from Pyrite in more efficient and environment-friendly ways such as bio-leaching. Scientists used Atom Probe, a specialised instrument that can detect impurities in minuscule quantities, as small as 100,000 times smaller than the width of human hair, and build a 3D map that shows precise locations of the impurities in the crystal of the material. On probing pyrite crystals, tiny imperfections in the crystals, also known as dislocations, can contain gold atoms, “decorating” the pyrite crystal with gold.
“This is particularly common where the crystals have been twisted during their history; here, gold can be present at concentrations several times higher than in the rest of the crystal,” wrote Denis Fougerouse, the lead author of the study, in an article on the Conversation.
According to the researchers, gold in crystal defects indicates that pyrite crystals with high gold content can form in a single process in the depth of the Earth, where the mineral is not as hard as it is on the Earth’s surface. Scientists also say that because gold being present in dislocations can offer an “enhanced partial leaching,” which bacteria can be used to attack and break down the crystal, releasing the gold. This process, called bioleaching, can potentially reduce energy consumption at a large level. However, this idea is still untested but scientists believe that it has enough merit to prompt an investigation.
Currently, gold mining costs 131.9 TWh of electricity annually other than producing tons of waste. Scientists think that if bioleaching of gold is developed to be fully functional, it can reduce the adverse print of gold mining on the environment.