The story varies, but the most common one holds that the initial discovery was made by a couple fishermen who noticed some small green rocks in a tidal mangrove swamp sometime around 2009.  Whatever the case, the find quickly led to thousands of people rushing to the swamp, hoping to strike it rich.  Workings would have to be abandoned daily when the tide came in, only to resume once the water left again.  Needless to say, the mangroves were ruined. 

Please note, the color will vary with light-- best in sunlight and light bulbs that mimic it, and progressively worse under fluorescent and incandescent lighting.