A chalice is similar to a goblet, but it is often decorated in a manner which denotes its connotations to the Christian faith; for example having the form of a cross or an inscription referring to prayer, God or Jesus.
For a vessel to be considered a chalice in the eyes of the Christian church, it often has to be blessed first. In the Roman Catholic church and some Anglo-Catholic churches, it was the custom for a chalice to be consecrated by a bishop or abbot.
Occasionally, without any evidence of religious decoration or ornamentation, we are able to decipher that a vessel would be considered a chalice rather than a goblet due to the style of the piece. Often a large, wider base signifies that it was used by many as part of a religious ceremony, furthermore the shape of the cup also indicates it’s use; a more square or triangular shape is more likely to be an attribute of a chalice, whereas often a goblet will have a more rounded, graduating form between the stem and the lip of the cup.