One of the earliest types of blown glass vessels is this elongated bottle with a short body and a long neck. These types of flasks were used to store the costly oils and unguents which were available from around the Roman empire, and the contents of such bottles could be poured slowly in tiny drops, and the small mouth was easily stoppered.
The iridescence on ancient Roman glass was unintentional, and was caused by weathering on its surface. The extent to which a glass object weathers depends mainly on the burial conditions; however, the humidity, heat, and type of soil in which the glass was buried also all affect its preservation.
