Mozambique is one of the countries where ruby deposits have been discovered in recent years. In 2008, rubies from Niassa, Mozambique appeared in the Tanzanian market, and the main ruby mining area in Niassa was Lichinga mine. Lisinga is located in a remote area of Niassa National Reserve. In 2009, Mozambique discovered the second ruby deposit, which is located between Pemba and Montepuzi (Figure 4-43), 225 kilometers north of Nampula. The ruby secondary deposit in Mozambique is located 25 kilometers east of Montepues. The largest ruby crystal in placer weighs 50 grams, and the faceted gem can reach 6 carats.

According to Thai jewelers, only 5%~ 10% of Mozambican rubies can be sold without heating, while other rubies with lower quality (70%~85%) are mostly suitable for glass filling.

Figure 4-43 Distribution Map of Main Ruby Deposits in Mozambique

Mozambique ruby ore belt is the product of Neoproterozoic to early Paleozoic geological movement in East Africa orogenic belt, which is mainly distributed in the eastern margin of Africa. Ruby occurs in altered gneiss, and the minerals in gneiss include actinolite, anorthite, andalusite, diopside, epidote, mica and red garnet. The research shows that the biogenic mineral combination of ruby is amphibole, kyanite and iron carbonate (siderite), which is similar to Tanzanian Winza ruby.

The color of rubies in Mozambique is mostly pink to deep red, often plate-shaped and weighing 40 grams. Hornblende is the most common mineral inclusion. There are relatively few untreated Mozambican rubies (mostly less than 3ct), and the most common treatment methods are heat treatment and lead glass gap filling.

The mining methods of primary and secondary rubies in Mozambique are simple, mainly manual mining, and there is no large-scale mining.