Beryl (aquamarine)

This spectacular group of prismatic, transparent, gemmy aquamarine crystals has great bluegreen colour and sharp crystal faces. Some of the crystals have needle-like inclusions of black schorl tourmaline. Aquamarine is a blue-green variety of beryl – a beryllium, aluminium silicate.

Erongo is one of the largest early Cretaceous granitic complexes in north-western Namibia. It has a diameter of 35 km and sits on the edge of the Namib Desert. The aquamarine crystals have grown in pockets in pegmatite veins in the granite. The pegmatites in which these crystals grew were unusually rich in beryllium and boron, major elements needed to make beryl and tourmaline. Other minerals in the pegmatite include topaz, fluorite, biotite mica, feldspar and quartz.