Islam doesn't have any official symbols as such, yet several symbols are strongly identified with the religion. These include the crescent and star, a sword, the color green and the Islamic statement of faith in Arabic calligraphy. The two branches of Islam -- Shi'a and Sunni -- share fundamental beliefs but have some different symbols of faith.

The Crescent and Star

The crescent and star symbol appears on the flags of numerous Muslim countries, most notably Turkey, Pakistan, Iran and Malaysia. In Turkey and other Muslim countries, the equivalent of the Red Cross organization is called the Red Crescent, and it is Turkey, or rather its earlier history as part of the Ottoman empire (1299 - 1922) that is the source of the crescent and star symbol. The crescent is thought to be associated with the new moon and the importance of the moon phases for Muslim festivals, such as Ramadan. The Ottoman Turks of Constantinople created a flag with a crescent on it, and later added a five-pointed star to it to represent the Five Pillars of Islam.

The Shahada

The Shahada is the statement of faith and the basis of Islam. Translated into English, it proclaims: "There is no God but Allah and Muhammad is his messenger." It is the first of the Five Pillars of Islam and used in daily prayer. To convert to Islam, a person must recite it three times in front of witnesses. Written in Arabic, the Shahada often appears on ceramic tiles used to decorate mosques and homes. It appears on the flag of Saudi Arabia to signify the importance of this country to Islam; Mecca, the main pilgrimage destination for Muslims worldwide, is located in the desert kingdom.

The Color Green

The Saudi Arabian flag has the Shahada printed on a green background and a number of other Muslim countries' flags prominently feature green. The importance of green stems from two facts: The prophet Muhammad's tribe, the Quraysh, had a green flag, and Muhammad himself frequently wore a green turban. It also says in the Quran, in Surah 18:31, that the inhabitants of paradise will wear green silk. Green is also a prominent color in Islamic decorative arts.

Shi'a Muslim Symbols

Islam has two branches: Shi'a and Sunni. These originate in the argument over the prophet Muhammad's successor as Muslim leader after his death. Shi'a Muslims believe that the prophet's cousin and son-in-law, Ali, was the rightful leader of Muslims, while the Sunni believe it should have been Abu Bakr, who was Muhammad's close friend, and the man who won the leadership. Shi'a Muslims are a minority in the Islamic world. An important Shi'a symbol is the double-pointed sword said to have been given to Ali by Muhammad. Some Shi'a also place the forehead on a turbah when they pray. This is a piece of earth made into a clay tablet that symbolizes the martyrdom of Muhammad's grandson. The earth is often taken from ground near his tomb in Karbala.