Vesica Piscis / Mandorla (The almond form) used as a logo for Visa Mastercard logo is an ancient form heavily used in Egyptians sacred geometry and later havily adopted by freemasonry and very occasiounallly used in Christianity in icons. The Vesica piscis is heavily used in new age and perhaps it is not a coincidence it is used as a insignia for MasterC ard Electronic Banking system – http://en.wikipedia.org/wiki/Vesica_piscis