The value of a pearl can vary from only a few dollars to millions of dollars. Some of the factors that influence a pearl's worth are its type, size, shape, luster and color.
Most pearls on the market are cultivated from farmed oysters. Natural pearls are increasingly rare and far more valuable.
"Luster" is the term that describes the quality of the pearl's reflection. Pearls with the sharpest, brightest and most distinct reflections are given a rating of AAA. Other ratings are AA+, AA, A and sub par.
The size of a pearl directly affects its value. Often, a 1-millimeter difference can significantly alter the pearl's price.