In the 16th century, the Spanish discovered what the Aztecs and Incas already knew: Colombian emeralds from the legendary Muzo district were more valuable than diamonds. Colombia holds the record for producing the world’s largest emerald crystal—a 7,052 ct. stone unearthed in the Cruces Mines in Gachala in 1969. The gem has long been regarded as a charm for good fortune. No wonder Dorothy’s eyes widened as the Emerald City glistened before her in The Wizard of Oz.?