I wondered that myself. Certainly unusual and very attractive earrings. No photo of the back of the pearl, would like to see. Also curious if lever back style was being used then. I'm not really familiar with antique jewelry.
I found an article on antique earrings which state that "Lever Back Pierced Earrings date to circa 1880. This type of finding features a fish hook style wire with a little lever that secures the earring. http://deniseyezbakmoore.blogspot.co.uk/2010/12/antique-tuesday.html. This is a very interesting article. This would fit in with the earrings being Edwardian or even older.
There are further photo's at the bottom of the listing. I thought they were baroque south seas each pearl is 14mm which is very large. They do have a beautiful orient and are very unusual.