This blown glass bottle is transparent, but shows pale gray shades. The patina adds a beautiful polychromy ranging from gold to violet-blue, whose appearance depends on the light.
After blowing a single parison, the glassmaker created the two sections by pinching the glass vertically, so as to form an inner wall: in our vessel, these two elements are totally separated, but other examples may contain two similar tubes that communicate at the bottom, by means of a channel. The handles, modeled in glass ribbons of the same color, were made separately: they served to suspend the object to a string. The lid, which would have been made of a perishable material (wax, cork, fabric, etc.), is never preserved.
These double-tube flasks are the elaborate and later version (they appeared from the 4th century A.D.) of the cylindrical, elongated cosmetic vessels that were very popular in the 1st century: they were intended to store kohl, a black powder used as eye makeup and probably applied, as it is today, on the edge of the eyelids. Already known in the 3rd millennium B.C., kohl also served as protection against eye ailments in the arid or semi-arid climates.
Such containers exist in many variants (double balsam jars would have contained a substance of two different colors) and were often excavated with small sticks provided with a bulbous end, which were used to take the kohl from the tube and apply it on the eyes: some were made of glass, while the more luxurious examples were made of bronze or carved from bone.