Star of David, Star of Rephan, Solomonic Star/"The Seal of Solomon", etc.

It seems to me that a star made from two equilateral triangles implies a society that understands geometry, trigonometry, etc. Also, this symbol figures into "Sacred Geometry". I believe this symbol, the swaztika and some other symbols show up again and again because they are pointing to naturally occuring phenomena, and putting the symbol in your tribe's works/art/etc. would be a way to show to all (including those who did not understand your language) that your tribe is not savage and instead is learned.