Star Tetrahedron

Star Tetrahedron or Stella Octangula
In the West, the representation of this form is associated with Leonardo da Vinci and
In the mystical tradition, particularly of the Cabala it is associated with healing.
One version is associated with a Merkaba Meditation which is predemoninantly a breathing exercise involving the chakras. Some claim that this approach goes back to ancient Egypt.  
In the Slavic tradition, the star tetrahedron and Merkaba have a deeper significance. The 3-D intersection of two tetrahedrons, one male, one female, is seen as crucial moment in the basis of creation.
 This star terahedron also occurs in 3-D and is sometimes shown as projecting a 2-D shdow.