Silk, a luxury good reserved for the wealthiest members of society, possessed a shimmering, light-reflecting surface so admired that it was called "the work of angels." Purple silk was popular among the elite, and the rarest purple was restricted for imperial use. Many silks were made in relatively simple lattice patterns. Finer ones, possibly woven at Panopolis (Akhmim) in Egypt, displayed detailed, animated figures from classical mythology often worked in two colors. The finest silks were elaborately woven in many colors to display exquisitely detailed figures. Patterns popular during the Byzantine era remained in use in the early Islamic period, as proven by scientific tests such as Carbon-14 dating. Silk originally came to the Mediterranean from China. Even in the seventh century, when silk was also produced in Byzantium, trade routes running past Samarkand in the north to Mecca along the Red Sea continued to carry it and other rare goods to the west. The Byzantines so valued the Red Sea trade route that the state aided the Ethiopian kingdom of Axum in its invasion of modern Yemen in the sixth century to ensure continued access.