QEMSCAN mineral map of pisoliths

QEMSCAN cross-sectional images of Pisoliths

The distinctive sub-rounded particles in this image are known as pisoliths, which form at the Earth’s surface as a result of weathering of a rock, typically basalt igneous rock. 

No two pisoliths are the same – although they generally have a nucleus and core which is then surrounded by several concentric layers.


Pisoliths can form a bauxite ore, the main source of aluminium.  

Extraction of aluminium from the ore involves a complex chemical digestion technique known as the Bayer Process. The efficiency of this process s is significantly reduced if impurities other than aluminium hydroxide (green) are present in the ore, such as quartz (pink), clays (brown) and iron oxides (orange) in the image.

FEI’s Automated Mineralogy solutions are helping mining companies better understanding ore variability in terms of mineralogy and textures. QEMSCAN mineral maps as the one above provided by courtesy of BHP Billiton lead to improved metallurgical processing.