Update of GRS type “Muzo green” emerald report policy

Lucerne, Switzerland – The 1st International Emerald Symposium held in Bogotá, Colombia, October 13-15, 2015 brought together leading members of the gem and jewelry trade from around the world. There, GRS presented its proprietary color-grading concept for emeralds called GRS type “Muzo green” which identifies stones with exceptional color saturation and hue.

Gathering helpful feedback from symposium attendees together with fruitful dialogue in which Dr. Peretti and expert panel members participated; a slight modification to the current Muzo Green appendices was created which reflects a more neutral phraseology. The small but valuable adjustment helps to clarify that the various emerald mines in Colombia can produce this very fine and strongly saturated color.

Below is the revised version of the emerald report appendix:

MuzoAppendixBorder 11Nov 2015 1



Citations related to the topic


Sauer, J.R., 1982. Emeralds Around The World. 1st ed. Rio de Janeiro: J.R. Sauer.

Muzo is the most famous of Colombia’s emerald mines. It has produced stones of matchless beauty for more than a thousand years. The rare, fine, saturated green crystals sometimes found there are the yardstick by which all other emeralds are judged.

This citation can also be found in Ringsrud, R., 2009. Emeralds, A Passionate Guide. 1st ed. Page 97: R. Ringsrud.

Morgan, D, 2007. Satan’s Crown to the Holy Grail: Emeralds in Myth, Magic, and History. 1st ed. Praeger.

For Colombian emeralds, the term “Muzo green” is often awarded to stones which have the desirable grass green or lime-jello shade. “Muzo green” emeralds don’t actually have the be from Muzo.

Jewellery News Asia. 2010. The magical ‘green fire’ of Muzo Emeralds. [ONLINE] Available at: http://www.jewellerynetasia.com/en-us/editorial/News/555/3775/the-magical-green-fire-of-muzo-emeralds. [Accessed 28 October 15].

“The Mogul emperors and the Maharajahs were so enamoured with emeralds that they had adorned their crowns and embellished their thrones with this gemstone. Their emerald collection was so extensive that people thought India had a secret mine centuries ago. Those emeralds actually came from Muzo.” – Mr. Gilles Haumont

Gemstone expert Gary Roskin, host of the Roskin Gem News Report and adjunct instructor of gemmology at The Fashion Institute of Technology at the State University of New York, said Muzo emeralds are known for their depth of colour and their richness of pure green with a hint of blue or yellow. “They can be found in large sizes and with wonderful transparency. Colour, which is the most important factor, size and transparency place Muzo on the mountain’s peak for the world’s finest emeralds,” Mr Roskin said. “Probably the most incredible nature of Muzo is that it not only produces the finest quality emerald in the world, it has been doing so since the Spaniards came to Colombia several hundred years ago, and possibly as far back as the 1500s.” “There are magnificent emeralds from other parts of the world, most notably Pakistan and Afghanistan; but Colombia, and Muzo in particular, because of its unique geologic formation, produces them in a consistent stream,” – Mr. Gary Roskin


Further readings related to the topic


Modern Jewelery/David Federman. 2015. Muzo Emerald. [ONLINE] Available at: http://www.modernjeweler.com/web/online/Colored-Gemstone-Gem-Profiles/Muzo-Emerald/1$524. [Accessed 28 October 15].

JFW Magazine. 2010. MAGNIFICENT MUZO EMERALD REACHES EXCEPTIONAL PRICE AT CHRISTIE’S GENEVA AUCTION. [ONLINE] Available at: http://www.jfwmagazine.com/jewels/news/524-magnificent-muzo-emerald-reaches-exceptional-price-at-christies-geneva. [Accessed 28 October 15].

Poly Auction Hong Kong. 2015. A SET OF EMERALD AND DIAMOND JEWELLERY, BY WILLIAM GOLDBERG. [ONLINE] Available at: http://www.polyauction.com.hk/catalog/catalogue_ecatalogue.php?id=3161&cid=131. [Accessed 28 October 15].

Geo Heavens Minerals. 2014. Emeralds from Colombia. [ONLINE] Available at: http://www.geohavens.com/index.php?option=com_content&view=article&id=170:emeralds-from-colombia&catid=82&Itemid=498. [Accessed 28 October 15].