Ankh, cross or crucifix: it still represents life & death.

In Egyptian mythology, only an immortal could handle a true ankh. If a mortal is touched by one it reverses their condition: the dead will rise; the living will die. Egyptians revered this symbol of life & death. They made copies to carry around with them, & eventually even smaller versions that could be worn. This tradition was continued by Christians, who only slightly altered the shape.