Pentacle

The pentacle (five pointed star, surrounded by a circle) symbolizes the figure of man with outstretched arms and legs. It stands for an integral personality; human/Microcosm; endless; power of perfection. In witchcraft, a reverted pentacle represents the devil's goat, and the witches foot. It's a sign of reversal of man's true nature.
(The figure stems from the alchemy and represents the unity of five elements: earth, fire, air, water and ether/quintessence; thus it also is a symbol for the super-natural.)
Pentacles are also often associated with creativity, material possessions, and wealth.

In most Tarot decks, Pentacles was (or is) one of the four suits of the Minor Arcana. In the Toth and Rider/Waite decks, the name has been changed into 'Disks.'