Writing about natural pearls can
sometimes feel like going down the rabbit hole from Alice in Wonderland. In order to explain the rarity of natural
pearls, one must first explain the distinction between these and cultured
pearls; then there is the plethora of different varieties of natural pearls
that exist to take into account. Though this may seem confusing to some, we
will try to clarify it here.
Pearls form in water-dwelling
organisms known as molluscs; they form when a foreign substance, be it a
parasite or dirt, infiltrates the shell (or shells depending on the variety of
mollusc). As a defense mechanism against this intruder, the mollusc will
secrete calcium carbonate (nacre) over it in order to protect itself. Oddly
enough, what is purely a defense mechanism for this organism is considered by us
humans as an eternally beautiful gem. This process can take numerous years to
come to fruition, much like everything else that is produced in nature and
unprovoked by humans. It is said by some that in order to find a single such
pearl that one would need to sort through and open thousands of molluscs
(generally oysters). Needless to say, when taking a second look at that Fabergé Pearl Egg from the last entry, it is truly awe-inspiring to think of the
time and work that must have gone into recovering so many pearls of such fine
quality. Cultured pearls form under the same conditions; only the intruding
body that will be covered in nacre is a bead that was implanted by humans. But
we’ll discuss the ins and outs of cultured pearls and their detection at a
later date.
That being said, natural pearls
come in all shapes and sizes. This is partly due to the water they were formed
in, as well as the variety of mollusc hosting them. For instance, pearls forming
in cold saltwater as opposed to warm saltwater will yield a generally smaller
pearl. Similarly, the pearls made in larger molluscs such as the pinctada margharitifera will yield not
only a larger pearl, but also different colors (black/grey undertones) than
let’s say the pinctada maxima (which
produces a gold or silver undertone). And because nature is wonderfully
imperfect, all of the pearls produced are uniquely shaped and very rarely
perfectly round.
Natural pearls from French Polynesia. Photo courtesy www.gia.edu/pearl-quality-factor |
There is a truly romantic quality
to natural pearls; much like finding that special someone, finding that perfect
pearl seems almost written in the stars.
Cool article!
ReplyDeleteIs there such a thing as a natural pearl with a pink or blue undertone? I've seen these in cultured pearl earrings and wasn't sure if that only happens because we mess with oysters chemistry or something?
First off, thank you for writing! It’s always a pleasure to interact
Deletewith our readers. To answer your question, I’d like to first clarify
what is understood by “undertone”. Generally, pearls have a base color which some may call undertone. The iridescent color or “orient” that rolls over the surface of the pearl is what we call an overtone. For instance, black pearls (like in the picture from the entry) are not simply black/ grey; their overtones can include green, violet and silver at times. That being said, you can find natural pearls in numerous colors. This will be dependent on the organism creating it. For example, freshwater pearls (both natural and cultured) naturally display pastel-type colors including pink due to the nacre secreted by freshwater mussels. Conch pearls produced from conch shells are also pink due to the secretion of the organism. This is in no way the result of human intervention. That is not to say that humans do not change the colors of pearls that we see on the market. Pearls can be heavily treated, be it by bleaching, dyeing and irradiation in order to improve their color. I will be happy to discuss in length the treatments that pearls can be subjected to in a later entry. I hope this helped!