Pearl

Pearls were not mined, they were the product of oysters or other mollusks, but they were treated like gemstones.

Description
Pearls were formed of layers of tchazar (aragonite) around a bit of grit or other irritant, growing inside a mollusk over the span of a few years. This slow process gave pearls a smooth surface with a deep, rich luster. Pearls were predominantly white but did occur in other colors such as gold, pink, or silver; rainbow and black being the most rare and valuable. The unique brilliant green pearls of the emerald oyster were valued at 500 gold pieces and above.

Over-sized pearls were frequently flawed in some way and not as valuable. One exception to this was a perfect head-sized pearl that was enchanted to become a crystal ball. A typical pearl has a base value of 100 gp to 500 gp, depending on market value.

Magic

 * Pearls were used as a material component in many spells, particularly those that reduced acids to plain water, and neutralize poison. Crushed to a powder, pearls were used in creating all types of magic mirrors. Well-known magical items included the pearl of power, the pearl of the sirines and the pearl of wisdom.
 * Pearls were used to create periapts of wisdom, common magical amulets often found in possession of high-ranking clergy.

Races & Sentient Creatures

 * Pearl was a common stone among the drow, a gem worn by drow of average station, albeit they used only those of black, red, or deep mauve colors.

Religions

 * Pearls were considered sacred by followers of Deep Sashelas and Dugmaren Brightmantle&mdash;appropriate for sacrifice, or to be consecrated for use, or recognized as boons or omens when found.
 * White pearls were sacred to followers of Savras.
 * Black pearls were sacred to followers of Shargaas and Vhaeraun. With the latter being known to occasionally send them to show his favor or disfavor to his followers.
 * The temple complexes of Blibdoolpoolp typically had large black pearls in them. Changes in their coloration were seen as favorable omens.