Pendulum - Malachite
Malachite is an amazing stone to work with, not everyone can though so if you find yourself getting headaches or feeling woozy hold a Rose Quartz, Blue Quartz or Fluorite along with a grounding stone while using malachite.
Communicate with Spirit by asking yes/no/maybe questions and allowing energetic vibrations to swing the pendulum to answer.
Pendulum Mats also available