SEVENSEAS Marine Conservation & Travel Issue 22, March 2017 - Page 81


Sylvia Gottwald

jewely, fine art, & conservation

TERIA PENGUIN'S MABE PEARLS. Pteria penguin, commonly known as the penguin's wing oyster, is a species of

marine pearl oysters.

Pteria penguin is native to the western and central Indo-Pacific region. The range extends from the East African coast and the Red Sea to India, southern China, southern Japan, the Philippines, Indonesia and northern Australia. It is found attached by byssal threads to a number of different substrates at depths of less than 25 m (82 ft).

Wild oysters of this species seldom contain pearls. When they do, they tend to be irregular in shape and have the same range of pinkish hues that are typical of the nacre lining the shells. Because the shell valves of this species are so thin, until recently it was impossible for oyster culturists to use it for pearl production.

Like all oysters they feed by filtration and consequently are very beneficial in cleaning the sea water and creating a healthy environment for other marine species.

However with new modern techniques, the seeding has become easier and Pteria penguin has become a major producer of cultured pearls. Most of the pearls produced by Pteria penguin are "mabé pearls", also known as bubble or half pearls, formed between the mantle and the shell valve and having one flattened side.

Naturally occurring spat can be collected for growing into mature oysters and there are even some hatcheries producing spat on a commercial scale.

These oysters are mainly cultured on the Ryukyu Islands, along the southern coast of China, on Phuket Island in Thailand and on Vava'u in Tonga.

They commonly display a silver color under the oyster muscle with a rich mauve, gold banding towards the black/brown outer-lip. In the past all semi spherical “half-pearls” used to be called “Mabe,” however, at present only the pearls that come from the Pteria penguin are called “Mabe pearls.”

The Mabe /Pteria oyster produces a brilliant nacre with a rainbow-like spectrum of hues, and the Mabe pearls produced from this shell, are commonly 12-20mm in diameter. As mentioned they exhibit uniquely penetrating brilliance, with hues ranging from light pink through deep rose-red to a "rainbow" pink. Sometimes the pearls have distinct gold-pink hue of high rarity.

Pteria Penguin is one of my favorite materials to work with in jewelry design. It is thin and easy to cut, it has lively changeable color surface due to fabulous golden hue as a background to a rainbow of colors.

The objects made of this shell exhibit lively movement because under different angles and light sources they look quite different.

The seemingly difficult wing shape of the shell is an inspiration and also a generator of exquisite dynamic forms for pendants, and brooches.

Sometimes the outer only partially polished black side of the shell is also useful when juxtaposed against the golden hue orientation of the inner side of the shell.

I often use Pteria Mabe pearls, sometimes framed in oxidized silver, a great juxtaposition of man made, almost industrial looking material against exquisitely rich hue of the pearls.

The necklace featured in this article is made of Blister pearls, which is a Mabe pearl with some surrounding shell material.

March 2017 Art & Culture