Hard, brilliant, precious, spherical concretion made of concentric layers of mother-of-pearl, produced by the epithelium of the oyster mantle to insulate the oyster and protect it from any inclusion by a foreign body.

Its name in ancient Greek, i.e. « Marguerite » ( ?) was derived from the Sanskrit « mrg », and it refers to the verbs look for, desire, purify, adorn, pray, etc.…

Only those pearls yielded in a natural fashion by a pearl shell, whatever its origin or wherever it came from, but actually brought about without human intervention, are entitled to be called natural pearls (decree 68-1089 of 29 November 1968).