Twelve Pearls gives everyone the opportunity to own and enjoy these stunning underwater gems. Our collection consists of Freshwater, Saltwater Akoya, Tahitian & South Sea Pearls. Whichever you choose, we're sure they will take pride of place in your jewellery collection and treasured forever.
Pearl Treatments
Attempts to improve gemstone appearance go back hundreds of years. Early gem historians reported first century practices of treating dull stones with vinegar to make them shiny, backing gems with silver foil to make them more attractive and more.
Some of those early histories described baking pearls in a loaf of bread to improve their surface appearance, peeling back nacre layers to reveal cleaner layers underneath, and soaking pearls in warm olive oil to “cure” surface cracks. A bizarre pearl cleaning technique described in a 2200 year old Egyptian text involved feeding a pearl to a chicken, then waiting an hour or so while the chickens digestive enzymes and gizzard stones worked on the pearl. The treaters had to kill the chicken to retrieve the pearl, but they apparently thought the results were worth the sacrifice.
Thankfully these days, pearl manufacturers have come up with a more modern approach! Post harvest processing can remove unwanted colour and some surface characteristics. Altering bodycolour – a pearl’s dominant colour – offers the most potential for pearl processors today. There are two common methods for changing pearl colour: dyeing and irradiation.
| Pearl Treatments | ||||
|---|---|---|---|---|
| Treatment | Purpose | Stability | Prevalence | Detection |
| Bleaching | Lightens dark spots; lightens some dark pearls to a brown "chocolate" colour | Stable | Routine for most types of light body colour akoya cultured pearls; Occasional for other types of pearls | Some detectable by advanced testing by a gemological laboratory |
| Dyeing | Imparts or changes body colour | Usually stable, but some colours may fade | Common | Some detectable by a trained gemologist, but often requires advanced testing by a gemological laboratory |
| Irradiation | Produces black, grey, or blue-grey colour in white or cream coloured pearls | Stable | Occasional | Some detectable by a trained gemologist, but often requires advanced testing by a gemological laboratory |
BLEACHING
Processors bleach most Freshwater and akoya cultured pearls. First they sort them by size, shape and colour. Then they immerse the cultured pearls in a bleach solution in large glass jars. They place the jars on wire shelves in small rooms flooded with fluorescent light. The cultured pearls remain in the bleach anywhere from a couple of weeks to a couple of months depending on the original quality.
Bleaching reduces luster slightly. To restore their luster, processors first wash and air-dry the newly bleached pearls. Then they tumble them in specially designed machines.
DYEING
In the late 19th century, the supply of natural colour black pearls declined. After some research, pearl processors discovered that pearls could be artificially “blackened” with silver nitrate, a product that’s used to manufacture photographic film. (It’s what makes the film light sensitive, so ti can capture images with light.)
IRRADIATION
Radiation technology brought about pearl-darkening process in the 1950s: irradiation with gamma rays. Gamma rays are similar to ordinary X-rays but have much higher energy.
In Freshwater cultured pearls, the gamma rays affect the nacre layers which can often give the pearls an intense metallic sheen with strong rainbow iridescence. This gives them remarkable orient!
In irradiated saltwater cultured pearls, the bead nuclei (a bead of freshwater mussel shell), not the nacre is darkened which means the result is the darkened nucleus showing through the nacre.