This contributor recently examined a strand of Chinese freshwater cultured pearls loaned by Jeremy Shepherd of Pearl Paradise, Los Angeles. They were produced at the same farm in Jiangsu Province as the so-called Souffl? pearls ("beaded" with mud) that began appearing on the market in September 2009, according to Mr. Shepherd.
The strand originally consisted of 23 cultured pearls weighing a total of 66.8 g; two were sacrificed for destructive testing. They were of baroque shape, ranging from 17.0 x 13.6 mm to 21.0 x 13.6 mm. Colors varied from white with a distinct purplish green overtone to light purple, purplish green, orange, and bronze with varying overtones; all displayed a pronounced metallic luster.
X-radiography of 13 of the cultured pearls showed beads with an off-round shape and features that strongly suggested that nonbeaded freshwater cultured pearls had been used. One sample was sawn in half, revealing a concentric structure surrounded by an outer rim of nacre. A second sample was broken apart with a jeweler?s hammer, confirming that a white freshwater cultured pearl of baroque shape had been used as a bead.
According to Mr. Shepherd, these cultured pearls were produced using the same type of mussel as the ?Souffl?s,? which some believe to be a hybrid of the Chinese Hyriopsis cumingii and the Japanese Hyriopsis schlegelii, though it may be a local variety of H. cumingii. It is highly likely that both the ?Souffl? pearls? and the ?pearl-beaded? samples described here are produced inside the mussel's mantle, probably in a later growth phase, by making use of existing pearl sacs that stemmed from a previous harvest.
- Elisabeth Strack
Gemmologisches Institut Hamburg, Germany