GREEN TREASURE: New York-based jeweler Bayco Jewels LLC took advantage of the opening day of the Baselworld watch and jewelry fair to unveil a one-of-a-kind 206-carat Colombian emerald it has dubbed the Imperial Emerald.

Bayco co-owners Moris and Giacomo Hadjibay hosted a cocktail at their stand Thursday to celebrate the acquisition, which they described as a milestone in the history of the family-run firm, which specializes in one-of-a-kind creations featuring precious gemstones.

“It’s a lifetime of work and achievement between the three generations of our business,” said Giacomo Hadjibay. “We have bought and sold the most important precious stones, but this is a completely different dimension from what we have done in 70 years of our family’s life in the jewelry industry, so we didn’t want to hide it.”

He noted that the stone has earned the highest grade certificates from global gemologicalentities. “All the laboratories, their minds are boggled by this,” he said.

Moris Hadjibay said his father had expressed an interest in buying the emerald years ago, but the collector who owned it only recently agreed to part with it. He declined to disclose the value of the gem, describing it as a museum-quality stone.

“To find a 10-carat emerald that’s clean is very rare. To find a Colombian emerald of more than 206 carats that has no enhancement, this kind of material, is unique in the world,” he remarked.