Pyrite 
Known as a protection stone and helps to ward of negative energy as well as physical dangers.
Pyrite is said to help against manipulative behavior, destructive criticism and controlling attitudes. It can also help you to remain calm and resolve difficult situations. 
The Pyrite stone helps to heal, activate and energize the Solar Plexus Chakra
Pyrite is also considered to be lucky, attracting opportunities, wealth and abundance into our life.