Throughout history, the pentacle has been the symbol of the Great Mother Goddess. It was the symbol of the Goddess Kore (Persephone in Greece) as well as the elements; plus one, Akasha or Spirit. Kore's sacred symbol was an apple, if you cut an apple horizontally, it will reveal a pentacle. Modern witches wear the pentacle as a symbol of protection and empowerment.
Many modern Wiccans wear a silver pentacle to draw in the magick of the moon, and some, depending on level and degree, adorn themselves with a gold pentacle to draw down the magick of the sun. There are still some who wear the pentacle forged with corresponding metals, example copper for Venus or Iron for Mars, to attract and harness planetary power. It is intuitively decided, by the wearer, what the pentacle is made out of.
Many, due to modern media and television, correlate this sacred symbol as the sign of the Christian Devil. That couldn't be more false! Modern Satanists use the pentacle, as well as the cross, as a way to pervert and distort the two religions-the pentacle has never been associated with devil worship. To wear the Star of Witches is to call upon it's magick for protection, wisdom, empowerment, and magick.