To answer that question, there are many different factors that determine the value of a pearl. To summarize, these are mainly size, surface, shape, color, nacre quality, and most importantly, luster.The Ideal Pearl Given that all factors are equal, the ideal pearl would be large in size. This is determined by the size of the mollusk they resided in. It would have an extremely smooth surface, and its shape would closely resemble a perfect sphere.No color is necessarily more valuable than the rest, but the ideal pearl would have a rich and deep color. Pink overtones are often preferred over green.It would have thick layers of nacre, until you can no longer see the center or the nucleus of the pearl. Lastly, it would be incredibly lustrous. Luster refers to a pearl’s ability to reflect light. The more light it reflects or the shinier it is, the higher it’s value. This is achieved when the layers of nacre are perfectly aligned.Having the ideal pearl in mind, we are now able to recognize the different factors that make a pearl valuable.