Zambia is the source of approx 20% of world-wide Emerald gemstone production. Most of the rest of the world production is said to come from Colombia. In ancient times the main source of Emerald was in Egypt, and remained so until European colonialists in South America encountered the Colombian deposits.
The attribution “Colombian Emerald” can add considerably to the cost of the gemstone, even when of not particularly fine quality, and more expensive than an Emerald of the same weight from Zambia, of good colour, transparency and tone.