Are conch pearls affected by ultraviolet rays in sunlight ?
All organic gems are affected by exposure to ultraviolet light, and conch pearls are not an exception. The effect of ultraviolet light may not be apparent until after prolonged exposure over many years. The color of conch pearls tend to fade significantly over time, the ultraviolet rays possibly destroying the color causing pigments. Thus it has been recommended that conch pearls be worn mainly in the evenings and not exposed to excessive sunlight. Even Black Tahitian pearls have been reported to have undergone fading in strong sunlight, as apparent from the story of the natural black pearl that lost its luster and color after exposure to sunlight in a jeweler’s shop window, as related in the “Book of the Pearl” by Kunz. The deep-pink color and flame structure of the conch pearls in the Queen Mary Brooch, has apparently remained unchanged for the last 100 years. This was probably due to the proper storage of the brooch during this period that prevented its exposure to ultraviolet light
