Originally formed as crystals in igneous rocks, such as granite, basalt and some metamorphic rocks, these minerals were eroded by wind, rain, frost, and rivers over millions of years. The resulting grains were washed down to the sea to become part of the coastal sands of ancient beaches.

In areas where high energy oceans occurred the lighter mineral sand grains, such as quartz sands, were separated, leaving concentrations of heavier mineral sands on beachlines. As the world’s ocean levels rose and subsided, the deposits were buried, and therefore they are often found more than 100 kilometres from modern day beaches.

The Murray Basin, which covers parts of Victoria, New South Wales, and South Australia, is an ideal location for this concentration process. Home to an ancient inland sea during the Cenozoic Era (up to 66 million years ago), large deposits of heavy mineral sands formed when heavy minerals entered the Murray Basin through river systems and the high energy Southern Ocean provided the concentration process.