Iridescence is an unintentional quality of some ancient glass objects that results in a gorgeous, multi-colored sheen when viewed from different angles. This occurs due to some areas of the surface degrading from moisture in the burial environment, which creates a thin layer of surface glass that covers a slight layer of air over the remaining bulk of the glass. As a result, light reflecting from the glass surface becomes broken into its compound colors, much as if it had passed through a prism, turning white light into beautiful colors.

AGE: 3rd-4th century A.D.

CONDITION: Excellent with no flaws.