Does a Chalice Have to be Made of Gold?
Technically, no. But it is perhaps the best metal suited for a chalice. The gold goblet after all is a longtime symbol of family and tradition.
There’s a more practical reason for a chalice to be made of “material that must be noble, durable, and in every case adapted to sacred use. In this sphere, judgment belongs to the episcopal conference of the individual regions.” (Inaestimabile Donum -Instruction Concerning Worship of the Eucharistic Mystery from the Sacred Congregation for the Sacraments and Divine Worship.). Everything else is highly BREAKABLE!
So more common or breakable items should not be used such as glass or clay but may be allowed by the Bishop of the diocese especially in countries where gold or another precious metal may be in short supply or difficult to buy or acquire. The idea is to guard against breakage.