From the stone history:

Peridot has been adored since ancient times and has been valued for centuries. People in the Middle Ages wore peridot to gain foresight and divine inspiration. Legend has it that pirates favored peridot to protect them against evil. Peridot was greatly prized by Egyptian Kings. Some of Cleopatra's emeralds were in fact peridots.

It is mentioned throughout the Bible, and early Christians considered it sacred. Today still, Catholic Bishops traditionally wear a ring of peridot and amethyst as a symbol of purity and morality.

Mystical power:

Peridot is used to help dreams become a reality. This very popular stone is believed to attract love. The deep green hue of the peridot also suggests a connection in wealth-attracting.
Peridot calms a raging anger. It is also useful to dispel negative emotions, and it is believed to promote sleep when worn to bed.