Bogota, COLOMBIA | Colombia is working to polish the reputation of its emeralds, which -- much like Africa's blood diamonds -- have lost their luster due to decades of violence surrounding the treacherous gemstone trade.

"The emerald's image is linked to that of Colombia, and Colombia is traditionally seen as being connected to war, drugs, trafficking," said Corentin Quideau, a French jewelry expert.

Considered the most beautiful in the world, Colombia's emeralds totaled $146.5 million in exports in 2014. And over the years, they've accounted for 50 to 90 percent of total global production.

But they've also been linked to bloodshed -- including a "green war" in the 1980s that killed 3,500 people.

Colombia's emeralds were the focus of a recent international symposium in the capital Bogota, the first of its kind, that drew several hundred participants.

The goal is to put the green gem back on a pedestal, said Quideau, brand strategist for Colombia's famous Muzo mine, whose past experience includes stints at big luxury labels such as Cartier, Boucheron and Louis Vuitton.

Located in the heart of Colombia, some 200 kilometers (120 miles) north of Bogota, the Muzo mine was first exploited by indigenous groups, followed by Spanish conquistadors starting in the 16th century.

It's here that the "Fura" was extracted -- an 11,000-carat, five-pound emerald that wowed the public when it was displayed in 2011.

"The color, the purity of these stones make them unique," said US expert Ronald Ringsrud, who speaks of Colombia's emeralds as if they were rare flowers. 

"They grow in sedimentary soil, a softer geological environment" that allows the crystal to thrive better than in granite, he said.

- 'Wild West' - 

For decades, the industry was dominated by Victor Carranza, a gun-toting peasant-turned-billionaire who gained control of the Muzo mine in the 1970s and fought off all attempts to take it from him -- including by feared drug lord Pablo Escobar.

The "emerald tsar" ran his operation with few scruples and alleged ties to right-wing paramilitary groups. He defied multiple attempts on his life and finally died of cancer in 2013.

He passed the company to his sole confidant, American ex-diplomat Charles Burgess, who set about softening its image.

He "set a goal of bringing the Colombian emerald to the same level as Colombian coffee: to turn it into a product that all Colombians feel proud of," said Burgess.

He brought out that slogan repeatedly at the recent symposium in Bogota, where industry insiders discussed putting the shine back on the country's emeralds.

Proposals included launching a national brand, "Mothergem," which Gabriel Angarita, the president of the Emerald Exporters Association, said would "distinguish Colombian emeralds as a unique gift of nature."

The Colombian Emerald Federation meanwhile proposed creating an International Emerald Committee to "promote sustainable development (and) support policies that favor the growth of the industry."

Individual mines are also getting on board, including the storied Muzo.

In the name of modernization and greater transparency, Burgess invested more than $100 million in Muzo and suspended production for two years to upgrade mining techniques and personnel management.

"Muzo emeralds are structurally very complex, nearly perfect. But when (the miners) used dynamite, it caused fissures in the stones," said Dante Valencia, a master gem cutter at the company's state-of-the-art workshop in Bogota.

"This used to be the Wild West," said Quideau, the French expert.

But things are starting to change, he said.

At Muzo, the 750 miners "have gone from a barbaric and archaic pay system based on the consensual theft of emeralds... to real contracts and salaries," he said.

Now mining firms need to ensure the traceability of all gems from the mine shaft to the retailer, he said, warning that some "traditional forces" in the industry are still resistant to change.