This suit, most often named "Coins" or "Pentacles", is a symbol for a magical talisman that represented wealth or potential. This suit represents something supportive that is available to you -- whether it be health, some kind of talent, a material or financial resource.
The Ace of this suit is usually pictured with a garden or agricultural backdrop, and symbolizes a seed. If this "talent" is planted and tended carefully, it will sprout and reward you with a good harvest. Think of it as a seed of your future fulfillment. An Ace represents the first step to a goal, and if that step is repeated, it will cover great distances. Generally, the suit of Coins are referring to the tangible realities in daily life, but in the case of the Ace, it could be symbolizing a winning idea, game plan or blueprint for eventual materialization.
Occult tradition sometimes interpreted this Ace as representing the alchemist's gold -- the light within matter, the 3rd eye of the energy-body. This recommends meditating upon the light within, and pointing oneself toward the archetype of humanity enlightened. By practicing such a meditation, one eventually gains enough control of the celestial radiance to heal the body, untangle the emotions and complete the growth of the soul.