This is how two companies work to turn the material from the Muzo mines into precious stones.

How to carve the precious stones in the Muzo mines One of the CTT carvers working on an emerald. Photo: Julián Galán
Emeralds have been extracted from the Colombian mountains since before the Spanish Conquest. The natives drew them attracted by their green color and carved them to represent figures. Many years later, beginning the 20th century, the European techniques of carving in precious stones, learned from diamond cutters and adapted to Colombian gems, arrived in the country.

Collecting this knowledge and with the latest technological advances developed for the emerald industry, in 2009 Colombian Transformadora SA (CTT) and Esmeraldas de los Andes (EDLA) began operating. These companies belong to The Muzo Companies, which has consolidated all the stages of the emerald value chain from different companies to implement the 'Mine to market' business model. Mining Texas Colombia (MTC) is in charge of exploring and extracting the material from the Muzo mines -recognized internationally for having the best emeralds in the world-, CTT and EDLA transform them into precious stones and Muzo Emerald commercializes them in international markets.

In 2014, The Muzo Companies acquired the exploitation rights of the mines to become the first Colombian operation of this type with foreign capital. According to Lucía Corredor, manager of CTT, "since then the face of the emeralds has changed by modernizing their mining and technical practices throughout the chain, providing complete traceability of their products and peace of mind to consumers".

Technify an art

Once the material is extracted from the Muzo mines, it reaches the hands of the carvers, who turn it into precious stones of the highest quality. The process begins with the preform stage, where experts analyze and select the stones and define a cut that ensures the highest quality and use of them. That is, if they are transformed into a square, rectangle, tear, etc., and whether facets or cabochons should be worked on. "We look for the personality of the stone, which is really what tells us what to do," explains one of the CTT preformers.

After the analysis, the stone is cut and rough. "This is the most critical step of the process, because it gives it the form of agreement with its cleanliness, color and clarity," Corredor adds. A bad cut can compromise millions of dollars and the quality of the products. That is why the workers in the production area of ​​CTT, which make up 80 percent of all personnel, have more than 15 years of experience as carvers, and in the case of pre-formants, more than 25.

Subsequently, the stones pass to the brightness of the square -face of the stone-, faceting, blunting and brightness. "The faceting is to make the lines that adorn the emeralds and the highlight is the design of the edges", explains a carver from the company. Since it began to operate, CTT launched a style of its own to be recognized worldwide. So all carvers use the same faceting technique that represents a brand seal. Finally, once the stone is finished, it passes through the hands of the master carver, who is in charge of quality control. With state-of-the-art equipment, verify that the gems meet the parameters of the company; check the geometry of the facets, the refraction of the light and the general appearance to ensure that the stone has life. "The company gives us the best equipment and we have the best emeralds. We have to do the best job, "adds one of the carvers. The process is under constant review and CTT is the only company in the sector that has obtained the ISO 9001: 2008 certification granted by Bureau Veritas.

The Muzo Companies report the total figures of their production to the State and in 2016, 88 percent of the payment of royal emerald royalties came from them. This information is a guarantee of traceability, because "we can say what day the emerald was born that we are delivering since we found it in the mine until it was carved. That's Mine to market ", concludes Corredor.