Strange Mushroom Pearl

by SSEF, first published in Facette 20 (January 2013)

The studied non-nacreous natural pearl.

In 2012, we again received a number of pearls with strange shapes for testing. The most extravagant and intriguing of these curiosities of nature was a non-nacreous brownish natural pearl from a marine mollusc, which closely resembled a mushroom (see photos). The pearl showed some flame structures, as it is known from various gastropods such as Melo Melo, Strombus Gigas (Queen Conch), Cassis Cornuta, and clams (Tridacna). X-ray microtomography analysis showed a complex structure of growth layers surrounding a central cavity, rather uncommon for such non-nacreous natural pearls.