Mother of Pearl (Pinctada maxima)comes from from the waters surrounding the Philippines and parts of Indonesia.
White MOP is the base line for most shell inlay. The photo here shows plain white shell, but livelier pieces can have briliant flashes of red and green. White is often used alone in very traditional inlays, or as an anchor for more exotic work. Because of its non-competitive nature, it is perfect where extensive engraving is required.