Helmet of Hermes

 made of various metals, life size

Mercurius - Hermes
(with affinities to Gemini and Virgo)

To the medieval alchemists Mercury was the metal symbolizing duality. Metallic yet liquid, matter yet spirit, cold yet fiery... Mercury was the metal uniting all the opposites…. Trickster, Journeyer, Guide of Souls… Known to the Greeks as Hermes, the messenger god…

Hermes was the protector of athletes, thieves, journeyers, and merchants... and in her book, The Gods in Everyman, archetypal author Jean Bolen points out that the physical substance of Mercury only adheres to precious metals... Metaphorically speaking - Hermes can show us the way to spiritual gold...

Luck :     "Hermes is the god of the unexpected, of luck, of  coincidence, of 'synchronicity.' The ancient Greeks would say: 'Hermes has entered our midst,' whenever a sudden silence had entered the room, descended on conversation and introduced into the meeting another dimension. Whenever things seem fixed, rigid, 'stuck,' Hermes introduces fluidity, motion, new beginnings - as well as the confusion which inevitably precedes new beginnings." - by Arianna Stassinopoulos, The Gods of Greece

from http://www.thezodiac.com/mercury.htm