Star of David.

 

The Magen David, or Hexagram, consists of two triangles; the downward facing one, representing the female, and the upward one, male. The symbol stood for Tantric eternal sexual union between the God and Goddess.

The Tantric "Great Yantra" was cabalistic sex worship that the Jewish tradition adopted during the Middle Ages, but the symbol didn't become official in their cult, until the 17th century;  however, they obscured its original meaning.