The trader is right about the labs. I have seen and discussed microradiographs with lab staff. They are saying if there is any evidence of a line or pear-shaped void, there is evidence of expellation, so they will call it cultured. What is to say that the oyster did not expel natural foreign matter and therefore would be a natural pearl?
Certainly, it would be preferable to see the call of indeterminate, rather than cultured, if it really is indeterminable. For natural pearl dealers, this is frustrating beyond belief, as a pearl must be submitted to multiple labs. How can someone market an expensive natural pearl without a lab report and realize a decent profit?
Labs are concerned with liability, a legitimate concern.
