What do you say about the use of glass chalices in Mass? Is this practice allowed by the Church, and if not, why?
I say that they are entirely forbidden, they may not be used, and anyone who uses them is sticking his thumb in the Church`s eye.
This is what you call a liturgical abuse.
All sacred vessels should be made of worthy and durable materials, which are precious and not porous, for obvious reasons. Thus, pottery and glass are not good materials for chalices.
The Congregation for Divine Worship a few years ago put out a document called Redemptionis Sacramentum concerning various liturgical abuses. It mentions this very thing.
3. Sacred Vessels
[117.] Sacred vessels for containing the Body and Blood of the Lord must be made in strict conformity with the norms of tradition and of the liturgical books. The Bishops’ Conferences have the faculty to decide whether it is appropriate, once their decisions have been given the recognitio by the Apostolic See, for sacred vessels to be made of other solid materials as well. It is strictly required, however, that such materials be truly noble in the common estimation within a given region, so that honour will be given to the Lord by their use, and all risk of diminishing the doctrine of the Real Presence of Christ in the Eucharistic species in the eyes of the faithful will be avoided. Reprobated, therefore, is any practice of using for the celebration of Mass common vessels, or others lacking in quality, or devoid of all artistic merit or which are mere containers, as also other vessels made from glass, earthenware, clay, or other materials that break easily. This norm is to be applied even as regards metals and other materials that easily rust or deteriorate.
A key word here is reprobated. This is a techincal term meaning that it is abolished, or forbidden in such a complete way that no one can appeal to custom (‘but we`ve been doing this for years now!") nor can anyone try to establish a custom by violating the law over a long period of time.
In other words…. NO GLASS CHALICES.