Black Pearl

Black Pearl (BP) is a rare type of pigmented concretion formed in the soft tissues of shelled mollusks. They are valued as a reagent in Britannian and  Serpent Islander magic.

Britannia
The majority of Britannian pearls are an iridescent white - formed when a piece of detritus finds its way past a mollusk's shell, where it begins to irritate the flesh therein. Black pearls are a rarity, said to occur only when a previously formed pearl is cast into the sea by an animal's death, such as that it comes into contact with a second host. Whatever their origin, they are seldom discovered, with a slight quantity of them regularly turning up along the cliffs of Buccaneer's Den. Such aberrations occur at a rate of one in ten-thousand pearls, and as such command a high price from aspiring mages, who use them in powdered form to imbue their spells with the elemental forces of kinetic propulsion.

Some confusion exists as to whether specimens for magical use must be perfectly spherical in order to convey magical potency. While the highly biased  Book of Fellowship and the writings of the mad mage Erstam make such claims of this reagent, Lord British's own aide, Philpop the Weary, explicitly states that the majority of black pearls used in spellcraft are imperfect, which seems a likely assertion given their widespread availability in Britannian markets.

Serpent Isle
While magically-inclined New Sosarians make use of black pearl in much the same way as their Britannian cousins, it should be noted that these reagents have an additional source on the cold lands of Serpent Isle, where they can frequently be found in the possession of the strange purple-hued magical gremlins which populate the land. 