The highlands of Northern Mozambique are dominated by a Precambrian basement section of the well-known Mozambique Belt that extends up north to the Mediterranean. In its basement, large regions were metamorphosed at high temperature and high pressure during the Pan-African tectonic event, 800 to 550 Ma (million years) ago creating suitable conditions for the formation of gemstones. Deposits of the Pan-African Orogeny are much older than the Himalayan range gem deposits (e.g. Myanmar rubies) that are only 40 million years old. The Montepuez deposit has both primary and secondary type of mineralisation. The secondary alluvial type mineralisation has been derived from the weathering of the ruby bearing primary host rocks, and subsequent transportation of the more resilient ruby grains along paleo alluvial channels.