Surely one of the most popular embellishments for card makers – pearls manage to be pretty and elegant without being overly showy, classy rather than brash I always think! Of course, the pearls we use are synthetic, but a real natural pearl is a thing of extraordinary beauty.
If you have been to see Mama Mia II (like me!!), you will know there’s a scene where a young suitor opens an oyster for his beloved (no names, no plot spoilers!) and there just happens to be a great big pearl nestling in it! In reality, finding a pearl in an oyster is very rare… but in fiction, of course, anything can happen!
So what is a natural pearl? I always think it is incredible how they are produced… Pearls are made when a small object, such as a grain of sand, is washed into a mollusc. As a defence mechanism to an irritant inside its shell, the mollusc creates a substance called nacre (mother of pearl). Layer upon layer of nacre, coat the grain of sand until the iridescent gem is formed. The ideal pearl is perfectly round and smooth, but many other shapes, known as ‘baroque’ pearls, can occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, ‘pearl’ has become a metaphor for something rare, fine, and valuable.
The most valuable pearls occur spontaneously in the wild, but are extremely rare, which is why they command such high prices. These wild pearls are referred to as ‘natural’ pearls. Cultured or farmed pearls from pearl oysters and freshwater mussels make up the vast majority of those sold. Imitation pearls are also widely sold in inexpensive jewellery – I think most of us of a ‘certain age’ probably own a string, but their iridescence is poor compared to genuine pearls.
Pearls are cultivated primarily for use in jewellery, but, in the past were also used to adorn clothing – think of the Elizabethans and their bodices encrusted with pearls. They are also been crushed and used in cosmetics, medicines and paint formulations.
Whether wild or cultured, gem-quality pearls are almost always pearlescent and iridescent, like the interior of the shell that produces them… hence the rather lovely term ‘mother of pearl’ as found inside the mollusc’s shell.
Cultured pearls are formed in pearl farms, using human intervention as well as natural processes. As with natural pearls, the initial formation of cultured pearls is the response of the shell to an ‘irritant’ – a tissue implant. A tiny piece of tissue (from a donor shell is transplanted into a recipient shell, causing a pearl sac to form into which the pearls structure starts to form. There are a number of methods for producing cultured pearls and one is by adding a spherical bead as a nucleus and most saltwater
cultured pearls are grown in this way.
So what makes pearls so beautiful? The unique lustre of pearls depends upon the reflection, refraction, and diffraction of light from the pearl’s translucent layers – the thinner and more numerous the layers in the pearl, the finer the lustre. So it’s the overlapping of successive layers causes the iridescence that pearls display. So now you know!