Mother-of-pearl necklace is more delicate than other forms of jewellery, such as solid gold metals or silver. When it comes to how to clean mother-of-pearl jewellery, a primary guideline to remember is to consider chemical-free, gentle touch, and washing the surface without using water.
The iridescent quality of the nacre (whether in pearl form or mother-of-pearl shell) is sensitive. It can be easily injured by excessive exposure to irritants such as water or chemicals such as chlorine present in pool water.
Second, exposure to hot water, such as in a shower, can destroy the nacre, so if you're asking if the mother of pearl can get wet, the answer is no. However, wearing them outside of the shower, pool, or beach is still suggested because pearls improve with wear.