natural and cultured pearls in estate necklace on eBay

[Caitlin]

Although I think it takes an advanced shopper to wrest bargains from eBay and it takes a savvy shooper just to not get taken, I like to peruse eBay periodically; it is a tremendous education, especially when I can bring questions here.
I wrote to this seller to ask what percentage of this necklace is natural pearls as they claim it is a combo of natural and cultured. What percent of natural pearls would make the price worth it?
http://cgi.ebay.com/Estate-Natural-Pearl-Cultured-Pearl-Opal-Necklace_W0QQitemZ300002940683QQihZ020QQcategoryZ92827QQrdZ1QQcmdZViewItem
I would really like to hear what the experts here think of this one

 

[Zeide Erskine]

Hi Caitlin,

This is almost impossible to tell because if any of the pearls are cultured, they are either the 5.3mm focals and vintage akoyas or all of the strand pearls could be modern tissue nucleated. The half pearls in the opal setting are most likely naturals. However, given their extremely small size, the value difference between natural seed pearls and cultured ones would not justify the cost of investigating which is which. This is not just because natural seed pearls are not very valuable but also because cultured seed pearls are more valuable than 4mm and bigger because of the cost of drilling and sorting pearls that small.

Zeide