“In ancient Indian mythology, the God Vishnu blew into a conch shell and made the first sound in all creation, a sacred sound known as “aum.” In Hinduism, the conch shell represents the five elements–earth, water, fire, air and space. In modern India, the conch shell is blown at the beginning of sacred rituals because of the belief that the vibrations emitted from the conch shell will dispel negative energy and purify the environment.
Adherents to certain aspects of New Age spirituality believe conch shells symbolize such feminine aspects as birth, regeneration, marriage and fertility. In China, some believe conch shells can bring good luck and ensure a positive experience in the afterlife. In Islam, the conch shell represents hearing the divine word, while ancient Greeks and Romans used the conch shell to symbolize their respective sea deities. The conch shell was even part of the belief system of the ancient Mayans, who believed its spiral shape represented infinity.” <from eHow>