Basic Information
A pearl is a gemstone of biological origin, created when a shelled mollusc (traditionally an oyster or clam) reacts to the irritation of a piece of foreign matter inside its shell by coating the object in layers of calcium carbonate based secretions, known as nacre. The resulting stone is typically pale and iridescent, with the most valued examples being perfect or near perfect spheres. Mainstream gem-grade pearls are expected to be pure white, but black pearls - being much rarer1 - have traditionally commanded a premium and other colours tend to vary according to fashion. Non-spherical "baroque" pearls can also vary in value, depending on their actual shape.
Also, the traditional pearl is from marine oysters - freshwater pearls and those from other species vary in value2 and "cultured" pearls (those created by deliberately planting grit in an oyster) tend to be less well esteemed as well. Artificial pearls, made from the nacreous lining of the shells of some pearl bearing molluscs are also sometimes circulated but tend to lack the lustre of true pearls and fail even casual inspection … although the same lining material, known as "mother of pearl" can be used in its own right for decorative purposes such as inlays.
Although not traditionally a "first order" gemstone, pearls have from time to time eclipsed them in value - the Romans esteemed them very highly indeed and the gemstone trader's prize in MAT 13 was, after all a pearl of great value.
In many places pearl diving - fishing oysters deliberately for pearls - was a significant industry, although one that is all but extinct in the modern world. In others, pearls were a bonus that accompanied the trade of oysters for food.
Besides their jewelry value, pearls have also been used medicinally - sometimes dissolved in vinegar - although any actual benefit beyond a placebo effect should probably not be expected. Mystically they have been connected with wisdom, "feminine energy" and a variety of other things. The pearl also serves as a useful allegory for turning a problem into an opportunity.
Sources
Game and Story Use
- Pearls were traditionally fished by free diving - until the introduction of reliable underwater breathing gear, pearl fishers would be a valuable source of diving personnel.
- Finding a pearl in your oyster makes a good narrative for those with ridiculous luck.
- Large, baroque or semi-baroque pearls can be extremely popular in pendants and the like.
- The original Dungeons and Dragons wilderness module X1: The Isle of Dread revolved around a legendary black pearl … this was later re-worked into something much more sinister in the WOTC/Paizo adventure path Savage Tides.