Nabatean Black cubes & Connection with other...?

Greetings E.A.,

 I was watching (re-watching) the one video podcast where you speak of the Nabatean culture and how the god that they worshipped were represented by small black cubes.  I was wondering what your thoughts are on the relation/connection between these representative black cubes and other religions that also use black cubes as symbols for their diety or representative power.  
 For example, the Kabha(the black stone) that is located in Mecca where muslims go to make a pilgrimage to, along with some orthodox jews who pray w/ Tefillin, the black cubes that are strapped to the forehead with verses of the Torah inside.  
 Do you think that its a coincidence that the black cube is representative as a form of power (or diety) between these several different cultures and religions?