In preparation for some galleries in the planning stages, the objects conservator has been checking the condition of some of our antiquities in storage to ensure they are in good enough condition to make an appearance. This ancient Roman glass jar from the 3rd Century AD has been brought to the conservation lab to be examined more closely under a microscope. Iridescent corrosion products can be seen covering most of the object. This corrosion is common in ancient archaeological glass, and happens when the porous glass absorbs moisture from its surrounding environment while it is buried. The introduction of moisture causes flaking, cracking, and the separation of layers in the glass.
The deterioration is not reversible, but it can be slowed by keeping the glass in a low humidity environment while on display. This will ensure there is no excess water in the air for the glass to absorb. Keep an eye out for this object going on display in the coming months!