Emeralds are a variety of beryl mineral group containing and have been cherished for their green colour for many centuries. Some of the earliest emerald mines were located in Egypt, Pakistan and Austria (Habachtal). The discovery of Colombian emeralds by the Spaniards in the 16th century led to an emerald revolution and to wide-ranging international emerald trading routes. At present, Colombia remains an important source of high-quality emeralds. Other important producing countries are Zambia, Brazil, Afghanistan (Panjshir emeralds), Russia, India, Madagascar, Pakistan and Zimbabwe.
The vast majority of emeralds found in the market are treated to enhance their transparency and appearance. Such treatments with which fissures are filled with oil or artificial resin need to be correctly disclosed.
Emeralds come in two types as they can be synthesised using two different methods: hydrothermal synthetic emeralds and flux-grown synthetic emeralds.