Amethyst pendulum on silver chain. 

Pendulums can be used to balance the chakras or the entire energetic system as well as individual organs or parts of the body.

Many people also use them for answers to simple yes or no questions.

The best way to choose a style pendulum is to use your intuition. Just because someone says a stone does or doesn't do something, doesn't make it true for you. I encourage you to use them as you feel called.