Pendulums are divination tools, used to answer yes/no questions to assist in providing direction.  They work by responding to your subconscious mind.
 
Labradorite
Associated with Third Eye Chakra
Labradorite is an excellent stone for helping you to discover the knowledge within.  It helps with new beginnings, including reinventing of yourself.  This stone would be especially helpful in questions involving multiple paths or outcomes.
 
This listing is for 1 pendulum intuitively chosen by me.