One of my absolute favorites. Here is what I have about Amethyst.
Amethyst
Dreams, Overcoming Alcoholism, Healing, Psychicism, Peace, Love, Protection Against Thieves, Courage, Happiness
Here is some information I've gathered about Agate, and some of the different forms of Agate.
Agate
Strength, Courage, Longevity, Gardening, Love, Healing (both physical and emotional), Protection, Protection from Bad Dreams, Stress and Energy Drains
Wear or carry while gardening...