Without a body of material from controlled excavations in western Iran on sites of the 7th and early 6th centuries BC the special character of Median metalwork is still largely a matter of surmise. Men and women throughout the Achaemenian Empire wore a rich variety of personal ornaments. For the 4th century the astonished comments of classical authors indicate the magnificent spoils which fell to Alexander the Great in the treasuries of Babylon, Persepolis, Susa and Ecbatana, where precious metals were often hoarded in the shape of vessels. What little evidence there is for the technology of fine metalwork in the Achaemenian Empire largely comes from Egypt. Throughout the Achaemenian period glass factories in Syria and Mesopotamia were producing multi-coloured glass beads, amulets, inlays and cored vessels in a manner and to patterns long established in the region. In Iran from prehistoric times engraved seals had been used to impress clay tags and tablets with marks of property and authority.