The chalice (cup, goblet) symbolizes the feminine aspect of the rituals, and is quite obviously related to the water element. The chalice is filled with blessed water (water of life) which is used in rituals and ceremonies for blessings on behalf of the Goddess. A chalice filled with water of life is passed on in a circle and each participant feels the power and grace of the Goddess.
In some cases, red wine can be poured into the chalice instead of water. Part of the wine is brought for sacrifice to the Goddess or/and the Guardians. The use of an athame with a chalice symbolizes the fusion of feminine and masculine in nature and in the ritual, and also resembles the union of the Goddess and God. If the chalice is held correctly, it resembles an open womb, ready to take upon the masculine beginning.
According to the tradition, the chalice is made out of silver, however many modern witches and practitioners use chalices and goblets made out of gold, copper, sandstone, ceramics, brass, crystal, pewter and other materials. Be cautious if you happen to use a copper chalice, as it is dangerous when used with wine (make sure the inner coating is not copper).