…as a defense mechanism when a foreign substance or irritant lodges itself in the shell of an oyster and cannot be expelled – accidentally in the case of natural pearls, and with human intervention in the case of cultured pearls. Body cells surrounding the irritant start secreting a substance known as nacre, which builds up over several years to form a pearl.
There are five attributes to consider when determining a pearl’s quality and therefore its value:
It is difficult for oysters to grow large-sized pearls. As a general rule, larger pearls are therefore more valuable. Two pearls different in size, may however share a similar value if the smaller pearl is superior in quality.
See the chart for more details on SIZE.
The more symmetrical in shape, the more valuable a pearl. Pearls can be round, pear-shaped, tear-shaped or oval. Oysters can grow pearls in many different shapes from perfect spheres to long, flat angel wings. Those irregular or asymmetrical in shape are termed baroque pearls.
See the chart for more details on SHAPE.
The orient of a pearl will determine the extent of its luster and shimmering iridescence. The more prominent its luster, the thicker the nacre. A thicker coating, will fetch a higher price.
See the chart for more details on THICKNESS.
The surface of a pearl should appear satiny smooth. You do not need a magnifier to detect blemishes as they will be readily apparent to the naked eye. When viewed carefully, both natural and cultured pearls may appear to have irregular surfaces. This is quite acceptable, but the clearer the pearl the higher the value.
See the chart for more details on SURFACE.
Although colour is a matter of personal taste, evenness in tone is important. Colours range from pink to white, silver-white, creamy-white, gold, blue and black.
See the chart for more details on COLOUR.
Proper care is necessary to keep pearls beautiful and lustrous. Pearls are organic gemstones, vulnerable to acid, alkaline and different humidity levels. Ranking only 3.5 to 4.5 on the Mohs scale, it may be scratched by contact with precious metals, other gemstones or sharp objects.