3. 1) A six-pointed star consisting of two superimposed triangles, one whose apex is up and the other apex down. The upward triangle is masculine, the downward is feminine—together they symbolize union of energies or sexual congress. In ritual magic they are used to invoke or to banish planetary forces.
2) One of sixty-four combinations of long and broken lines used in the I Ching (or Yi King) system of Chinese divination that are traditionally determined by throwing Yarrow Sticks, or by means of coins (heads, tails), dice, dominoes or other means.
3) As a symbol, it is the Hebrew "Star of David."
Suggested Reading:
Regardie, with the Ciceros: The Tree of Life: An Illustrated Study in Magic
Kraig: Modern Magick: Twelve Lessons in the High Magickal Arts
McElroy: I Ching for Beginners: A Modern Interpretation of the Ancient Oracle
Nishavdo: I Ching of Love—a boxed set of 64 illustrated cards with booklet.