Amethyst

Amethyst is a powerful and protective stone.  It guards against psychic attack, transmuting the energy into love and protecting the wearer from all types of harm, including geopathic or electromagnetic stress and ill wishes from others.  Amethyst is a natural tranquiliser, it relieves stress and strain, soothes irritability, balances mood swings, dispels anger, rage, fear and anxiety.  Alleviates sadness and grief, and dissolves negativity.  Amethyst activates spiritual awareness, opens intuition and enhances psychic abilities.  It has strong healing and cleansing powers. 

In ancient times, it was thought that natural amethyst could purify the body of all toxins. Ancient Greeks believed that the stone protected the wearer from drunkenness and enabled them to keep a balanced mindset. Wine was sipped from goblets incorporating amethyst stones to prevent inebriation, and stones laid on the sick to draw out infection.

I would hold a piece of amethyst when feeling anxious, focus on your breath to help calm you down.