Well, I'm not sure exactly what this headline means, as the text of the artitcle said nothing about this emerald bead (it is not a green-colored pearl, it is a polished emerald bead) being found in the mouth of Cao Cao's mummified remains!
Rare emerald pearl inserted in Cao Cao's mouth found
13:12, June 12, 2010
The first 100-square-meters chamber of Cao Cao's tomb has been ransacked by thieves many times, but archaeologists still unearthed nearly 300 complete artifacts from it. Of those, the most special and valuable is the emerald pearl. According to an expert on collection, the pearl could be the only one in the world and nobody has ever seen it except in history books.