I want to direct your attention to a fantastic resource on the web for ancient art, including plenty of ancient glass. It is the Yale University Art Gallery, and it is located, obviously, at Yale University in New Haven, Connecticut. I've never actually been there, although it's on my list of To-Visit Museums, but I have utilized their online resources, image gallery, and downloadable guide.
Their Ancient Glass: Guide to the Yale Collection is available here, and contains some excellent images and information about glasswork and artifacts in their collection.
I'll be back later this week with a post about mosaic bowls!