Natural pearl necklace with one imitation pearl

Our testing not only revealed the presence of 40 natural pearls of a quite remarkable diameter (8-11 mm), but in addition one imitation pearl consisting of a plastic bead covered by a ‘lacquer’ coating that seeks to mimic a pearly lustre.

by Dr. M.S. Krzemnicki, first published in Facette 27 (June 2021)

Figure 1: Natural pearl necklace containing one imitation pearl. Photo: A. Chalain, SSEF.

Even after having tested literally hundreds of natural pearl necklaces in the lab, it does not mean that we can’t expect surprises.

In the last SSEF Facette (No. 26, page 40) we described the astonishing case of a cultured pearl necklace with one natural pearl mixed into the pearl strand. As a recent addition to this club of extravaganza, we can present this year the following beautiful pearl necklace (Figure 1). Our testing not only revealed the presence of 40 natural pearls of a quite remarkable diameter (8-11 mm), but in addition one imitation pearl consisting of a plastic bead covered by a ‘lacquer’ coating that seeks to mimic a pearly lustre (Figure 1). Interestingly, the imitation was mostly transparent to X-rays, which had all SSEF gemmologists gravitating towards the black ‘hole’ present in the radiography of this necklace (Figure 2). It was only through the brave intervention of Luke Pearlwalker that we could avoid larger damage to our team.

As these cases show, the addition or substitution of a pearl during repair and restringing of a pearl necklace obviously may sometimes lead to surprising results.

Figure 2: The imitation pearl is strung between these two natural pearls partially visible on the top and bottom of this radiography. As the imitation pearl is transparent to X-rays, it leaves a black ‘hole’ between these two natural pearls strung on the pearl strand. Photo: SSEF.

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