Pardon me whilst i nerd out.
"The Art of the Anglo-Saxon Goldsmith" by Elizabeth Coatsworth and Michael Pinder, printed 2002 by The Boydell Press
(the scad library has it but i wants my own!)
There's also a source reference to something called "Aspects of the Production of Early Anglo-Saxon Cloisonne Garnet Jewelry" by A. H. McFadyen, which turns out to be an unpublished PhD thesis from Manchester Metropolitan University or somesuch. [pout]