Hi and welcome to Pearl-Guide!
They look like they could be SSP. They do not look to me like imitations -- they are not completely matched in color, luster or overtones.
There are now large freshwater pearls that are sometimes misrepresented as SSP.
What size are these pearls?
Are they undrilled?
Approximately what is their price?
Where are they being sold from-- where in the world?
If they have any blemishes could you post a photo of them?