Description: Illite-kaolinite (argillic) altered granite containing quartz veins with illite, tourmaline and chalcopyrite.
Origin: Mill pebble from the Los Bronces porphyry-Cu deposit in Chile.
Whole rock geochemical composition (selected elements): Cu: 0.96%; Si: 32.84%; Al: 9.58%; S; 0.66%; Fe: 1.15%; K: 5.02%; Na: 0.88%; Mg: 0.20%; Ca: 0.05%.
Qualitative XRD analysis: Quartz, plagioclase, K-feldspar, mica, tourmaline, rutile?, chalcopyrite?, chalcocite?
Acknowledgement: Anglo American and Delft University of Technology are thanked for providing the rock sample and geochemical data. The hyperspectral image was acquired by Abigail Agus with a camera that was made available by Specim Spectral Imaging Ltd.
