Very obviously dyed black Freshwater pearls, but they are on the up and up about the fact. I took a look at their Authenticity Certificate
http://www.yourpearlplace.com/page/997807
Although there seems to be some confusion regarding the distinction between Saltwater Oysters and Freshwater Mussels
it does appear that they are honest. Ridiculously expensive and slightly misinformed, but they aren't trying to dupe customers.