The Pentacle is usually a flat piece of pottery, metal or wood, inscribed with a 5 pointed star.  It is used as the centre piece for the altar and items are placed on it for consecration and blessing, such as salt, water, and also amulets and charms.

 

The Pentacle is the primary and best known symbol of Wicca, and is also a traditional symbol of protection.

 

The Pentacle is the tool of the North, and is associated with Earth.  It is a feminine in nature, and represents the Goddess.