The glass jewelry from Lacoste has been the subject of an indepth archaeometric study, in parallel with the typochronological study. The aim of this article is to give a summary of the methodology adopted as well as the issues addressed, through a number of specific examples: a series of bangle fragments decorated with bumps/bosses, a group of beads with spiral decoration, and of a block of glass. Questions concerning technology and composition have first of all prompted numerous macro- and microscopic observations, and have furthermore helped to establish a range of analytical protocols with the aim of identifying the chemical constituents of each item. In bringing this data together, a number of discussions have arisen concerning Celtic glassworking practices, and the status of glass at Lacoste.