Islamic grafitti may help solve Qur'an mystery

A 7th century inscription in stone by an Arabic traveler may help solve a mystery about the Qur'an pondered by scholars for centuries: Why was the text seemingly written without diacritical marks?

The inscription, which is the earliest known Arabic writing, "shows evidence of a fully-fledged system of diacritical marks," according to researcher Ali ibn Ibrahim Ghabban. The sandstone was found in Saudi Arabia.