Conch pearls are one of the most rare and valuable of all natural pearls. It has been estimated that approximately 1 in 10,000 conch produce a pearl and of these only a few possess the color, shape and flame pattern necessary to be considered a gem. The color of conch pearls varies greatly. Pearls are most often found white, brown, beige, yellow, orange, pink, or red. The latter two being the most sought after.