Answered By: Regan Brumagen Last Updated: Nov 22, 2016 Views: 15
From Kelley Elliott (curatorial assistant):
At this time we do not know any more details about the enamel solution or how these pieces were made. From what I have read, each piece was heated at different temperatures and for different lengths of time. The process is still a bit of a mystery. Eventually our conservators will take a look at the chemical composition of the clear overcoat of the gemmaux as well as the adhesive used to hold the glass pieces together.