As Zambian emeralds continue to carve a sizable niche in the world of jewelry, Francesca Fearon investigates.

This question is rather topical as the launch of the Muzo Emerald brand is throwing the spotlight back onto Colombian gems at a time when the Zambian variety has carved a sizeable niche in the world of emeralds.

This golden globe and cross, from Muzo Emerald, is set with 36 Colombian emeralds and said to be worth $500m.

Colombian emeralds have a history that dates back long before the Spanish Conquistadors arrived in South America in the 16th century and started trading the gems with the Indian Moghuls. Zambian emeralds are much younger, discovered in the 1920s, but not properly mined until the 1970s and now sustainably managed by Gemfields, which took control of Kagem, the largest emerald mine in the world, in 2008.

Without getting too swept away by geology, these stones come from the beryl family and derive their silky, rich green colour from the presence of chromium and vanadium. African emeralds differ slightly because there is less vanadium, while the additional presence of iron gives them a bluish undertone. Chromium gives the emerald its fluorescence, and disrupts the crystal structures with inclusions that infuse the emeralds with beautiful “jardins”, which are particularly noticeable in Colombian emeralds.