Dear Frank:

Glass vessels are not to be used. Any vessel that can easily be broken is not permitted.

More specifically, the General Instruction of the Roman Missal (2002) states:

328. Sacred vessels are to be made from precious metal. If they are made from metal that rusts or from a metal less precious than gold, then ordinarily they should be gilded on the inside.

329. In the Dioceses of the United States of America, sacred vessels may also be made from other solid materials that, according to the common estimation in each region, are precious, for example, ebony or other hard woods, provided that such materials are suited to sacred use and do not easily break or deteriorate. This applies to all vessels which hold the hosts, such as the paten, the ciborium, the pyx, the monstrance, and other things of this kind.

330. As regards chalices and other vessels that are intended to serve as receptacles for the Blood of the Lord, they are to have bowls of nonabsorbent material. The base, on the other hand, may be made of other solid and worthy materials.

A commentary in Canada (well know for its liturgical irregularities) called the "Vision of the Eucharist" said that "durable glass" could be used for sacred vessels. Durable glass is rather an oxymoron, but is also not the "noble and solid" and "worthy" material that the 1975 General Instruction required. Glass stemware is a common material and thus is not suitable for a sacred vessel.

The 2000 Instruction was more specific in its language requiring sacred vessels to be "noble and metal" with preference given to materials that do not break easily or deteriorate (GIRM 2000, 328)

The 2002 General Instruction is even more specific. It seems that with immature people, one must be very specific or they will take advantage of any slight vagueness like little children.

Even more recently the Congregation for Divine Worship in 2004 decreed in Redemptionis sacramentum:

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. [emphasis added]

Your priest needs to be informed of the Church's legislation on this. If he wishes to rebel against the Church, then a report to the bishop is warranted.

God Bless,
Bro. Ignatius Mary