You may have been admonished for casting pearls before swine, but the greater sin is casting fake pearls before scientists. Why? Scientists in Switzerland have pioneered a method for extracting DNA from the core of a pearl, revealing not only the authenticity of the gem, but also the age and origin. Being able to record the DNA fingerprint of a pearl gives both jewelers and consumers more transparency in identifying pearls of dubious or intentionally misleading provenance. But how does one harvest DNA from a pearl without destroying it? To better understand that, it behooves the pearl enthusiast to reflect on the organic origins of the gem.
Both natural and cultured pearls result from a mollusk responding to an irritation of its soft tissue, most often a parasite or injury and not the fabled grain of sand. Layer by layer of a mineral and organic composite called nacre wraps about this irritant and soothes the oyster’s delicate flesh. In time this becomes the pearl, having trapped within its many lustrous layers the secrets of its time and place. By shaving off small filings of pearl, scientists may isolate the organic compounds (together with any stray bits of tissue that may have been trapped like a mosquito in amber) and interrogate the DNA.
But the pearl! Surely this technique would be too invasive and damaging to a pearl of extraordinary quality or rarity? Thankfully, scientists may work within a pre-drilled core, essentially ‘scraping’ DNA from the inside of a pearl already pierced for stringing or mounting in jewelry – with no outward indication of trauma. Of course, completely whole pearls that haven’t yet been fashioned into jewelry would be subjected to a prick or two.
Pearls of great historic or cultural significance, like those in the Crown Jewels or other famous collections, may now be as easily understood and chronicled as pearls emerging within the last few years. The analysis is astonishingly accurate, being able to pinpoint the particular provenance of a pearl down to the specific lagoon or bay from which it emerged. This is yet another accolade for the pearling industry, which prides itself on transparency, sustainability and environmental friendliness – another reason that today is a good day to wear Spey pearls.
Image: Pinctada radiata pearl with a soft blush overtone, Eilat, Israel. Credit: ChameleonsEye.