Greenstone

A type of compact igneous rock with high chlorite levels caused through alteration. Archaean greenstone belts are widely found in ancient rock systems and are often host to productive auriferous deposits such as Hemlo in Canada and the area around Kalgoorlie in Western Australia. Lode gold deposits associated with Archaean greenstone belts have been mined in Brazil, Canada, China, India, South Africa, Western Australia and Zimbabwe.