The correct name is Strombus Gigas, in English also known as Queen Conch, it's a monovalva shell that prefers the warm waters of the Caribbean Sea and the sandy shallows near the coral reef.
It is drawn more for food in Honduras, Haiti and the Dominican Republic.
It can be white or off white but its internal state is bright pink, white or orange. The maximum length of this shell is 32cm and weights about maximum 3kgs, the most common type measures about 24cm .
It's a sea water clam pearl, the pearls are found only in very few cases, in fact, the pink pearls or, more properly known as conch pearls, are very rare and therefore expensive. You can obtain necklaces, various shapes such as flowers, animals, suns and moons, feathers, leaves, cameos and whatever the customer requests.