Glass chalices

In Paul Turner's Blog by Paul Turner

Q:  I looked on your website/blog, do you have anything on the use of glass chalices permitted or not? I know what the GIRM says but it could be interpreted loosely.
A:  GIRM 330 says “As regards chalices and other vessels that are intended to serve as receptacles for the Blood of the Lord, they are to have a bowl of material that does not absorb liquids. The base, on the other hand, may be made of other solid and worthy materials.” But GIRM 328 says, “Sacred vessels should be made from precious metal.”
And Redemptionis Sacramentum 117 classifies glass as among the materials “that break easily.”
So, no, we’re not supposed to use glass.