Could be called "pixie dust" and may also be known as "fairy dust", it is a fictional substance. It is a trail of sparkling material that often follows mythical creatures such as pixies and fairies in general when they are visually represented. Sometimes, this trail is interpreted as being a tangible substance, often imbued with magic powers.
Taken to normal realms of human existence, one could use it to describe bringing forth help from the ethereal, or heavenly spirit, to cause something humanly impossible to happen.
"It took magic dust to get her to let me in her pants."