Welcome to PearlGuide. These appear to be Chinese Freshwater bead nucleated pearls which have been either dyed or treated with silver nitrate to create these colors.
Yup, Marianne is right. Big dyed Chinese freshwaters. They look lustrous and have some variety of colour, mid quality for this sort of pearl (you mentioned that they have sharpish ridges).
I suppose I am disappointed to hear this news. But they really are lovely. My purist mind will need to think about this new information. I paid about $150 for them on looks alone. Only later did I start to wonder......................after seeing "peacock pearls" listed on auction sites like EBay for $50 and less.