On Treated Chocolate Pearls.

Jewelers Circular Keystone, May, 2007

By Gary Roskin, G.G., FGA

SSEF, the Swiss Gemmological Institute, Basel, Switzerland, examined several chocolate pearls, currently popular, from three producers. The SSEF Laboratory reports that the pearls were dyed, showing 'distinct color concentrations' in the very top layers of nacre, below which was seen gray to lighter brown color. SSEF called the under color layer 'not darker, as indicated in the propaganda material.'

'This situation relates to simply stained pearls, as it has been commonly done with silver nitrate or today with more modern dyestuffs,' says the SSEF report. The test for silver proved negative on four pearls. 'Another coloring agent must be in use,' SSEF writes. 'Such a dyeing treatment could also transform white or gray...

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