The home of the most beautiful Colombian emeralds is in the Eastern Cordillera (Oriental) between Cundinamarca and Boyacá in the eastern ridge of the Andes Mountains. The tree main mining areas are Chivor, Muzo and Coscuez.
Before the arrival of the Spaniards in 1499, the indigenous people of Boyacá had already begun the extraction of the emeralds in the region. Archeologists estimate that the native people commercialized these gems in 1000 AD. Once the Spaniards had established in Colombia, in the different regions, they exploited the gems that ended in the hands of European aristocrats and mogul governors of India.
During the colonial period, miners extracted emeralds by following the veins end because of the mine issues some works were abandoned in the mid-1600’s. Work was retaken nearly two centuries later and using more modern techniques at the Coscuez mine. These works led to the discovery of a mineral called parasite, a rare fluorocarbonate of cerium. Little has been said about the Coscuez mine activity lately. It has been repeatedly worked, abandoned, and reopened.
As for the Muzo mine, it has a long history that started when it produced most of the emeralds in the region in the early 1900’s and it was eventually taken over ECOMINAS to try to control illegal mining and back marketing of emeralds. This was a success due to the increase in the exported emeralds.
The government control of the Colombian mines has been of help to bring peace into these areas where there was conflict between the drug cartels, government, and emerald mining families.
Regarding the geological setting of the emeralds, there are three main types of deposits where they can be formed: magmatic-metasomatic; sedimentary – metasomatic and metamorphic – metasomatic. Colombia’s emerald deposits are sedimentary – metasomatic. Most of the emeralds are hosted predominantly in shales of the Cretaceous (formed more than 65 million years ago), which makes them unique in the world. The tectonics of the area created the perfect blend for the emeralds to form.
About the mining methods used to exploit the emeralds, it has changed over the time, some of the techniques used are open-cut mining, tunnelling and use of heavy machinery, as open pit and underground mines.
The open-cut mining was used mostly because of the steep slopes of the formations covered by the jungled that could only be worked in great terraced banks. The limestone and shale make it easy to remove the emerald crystals. The stones are then separated into several grades according to color, size, transparency, and impurities.
Tunnelling was used as of 1987 in Muzo mine because of the very limited gems found near the surface. Mining of emeralds seem to be a very manual method and there were even some “guaqueros” (treasure hunters) that would dig through the debris in the hopes of finding emeralds missed by the workers. Tunneling method has limited the number of treasure hunters because of nature of the technique.
Colombia is second on exporting emeralds just after Zambia. More than 80% of the exports go to the USA, Hong Kong and Switzerland.
The world of Colombian emeralds is fascinating, however there is very limited information on the production and mining methods used by the mining companies in Colombia. It would be important that companies publicly share their discoveries with the world.
Dice, S., & Dice, O. M. (2020, May 11). Minería de esmeralda en Colombia: Minería en Línea. Retrieved from https://mineriaenlinea.com/2020/04/mineria-de-esmeralda-en-colombia/
Ringsrud, R. (1983). The Coscuez Mine: A Major Source of Colombian Emeralds. Retrieved from https://www.gia.edu/doc/The-Coscuez-Mine-A-Major-Source-of-Colombian-Emeralds.pdf
Colombia Emerald Mines – A Guide to Colombian Emerald Mining. (2021, May 12). Retrieved from https://www.emeralds.com/education/mining-locations/colombia-emerald-mines/
Colombia Emeralds: Investment Sought as Exports Spike. (2021, June 11). Retrieved from https://www.bizlatinhub.com/colombia-emeralds/
Jewellery Appraisers of the World. (n.d.). Colombian Emeralds from the Muzo, Coscuez and Chivor mines. Retrieved from https://www.ja-world.com/consumer/emeralds-from-muzo-coscuez-chivor.html