Only until recently has there been scientific evidence as to how pearls grow into different shapes. We now know that as a pearl grows, it turns constantly, as the oyster or mussel wraps thousands of layers of a liquid crystalline substance called nacre, to create the pearl as we know it.

Typically, through the months or years it takes to grow a pearl before it is harvested, the oyster will shift the pearl- causing the layers of nacre to coat un-evenly, causing the shape to warp, either equally, or unequally. Therefore, the resulting pearl at harvest is rarely perfectly round, but more often a variety of different shapes.