Pendulums are divination tools, used to answer yes/no questions to assist in providing direction.  They work by responding to your subconscious mind.
 
Rainbow Moonstone
Associated with all Chakras
Rainbow moonstone is associated with the emotional body.  It can help with questions dealing with stress, trauma, balance, as well as sources of joy & optimism.
 
This listing is for 1 pendulum intuitively chosen by me.