Here in the Tucson show there are a lot of Afghani dealers showing what are supposed to be roman glass fragments found in Afghanistan. I always have my doubts when I see a number of dealers selling goods that are hundreds of years old. How can there be so many currently available? But I don't know of any way to artificially age and iridise pieces like this so they may be real.
The only dealer I can remember is Indus Valley, 5459 W Mosquito Dr, Tucson AZ 85742, 520-744-8094 No website but you can e-mail them at kuchi_indus at hotmail.com. (Change that to a regular e-mail addr.) I happened to pick up that card but have no idea about their quality or price.