Using only water and gravity to retrieve gold from the crushed quartz ore meant that much of the gold was lost. Miners began to use mercury to get more of the gold from the crushed quartz. The mercury absorbed the very fine particles of gold until it became an amalgam, a combination of gold and mercury. The amalgam was then easier to collect, but it had to be further processed to separate the mercury from the gold. The amalgam was placed in a chamois bag and squeezed to remove as much of the mercury as possible. Afterwards the remaining amalgam was heated, evaporating off the mercury. The leftover gold was melted to bars or ingots.

Mercury amalgamation was used along with gravity methods to increase the yield of gold from quartz-bearing ore. In stamp mills mercury was added to the water that washed over the crushed quartz. The material was carried over a copper plate and through a series of sluice boxes designed to trap different sized pieces and particles of gold. When a certain amount of the amalgam had collected, the mill was shut down while the gold and mercury amalgam was scraped and washed off the copper plates and sluice boxes before it was further processed.
  
Art Gallery of Nova Scotia, Dian Day, Susan Sellers, Rita Wilson

Nova Scotia, CANADA
© 2013, Art Gallery of Nova Scotia. All Rights Reserved.

Teachers' Centre Home Page | Find Learning Resources & Lesson Plans