Agate strengthens relationships, promotes composure and offers a warm, protective quality to the wearer. Tree agate is also believed to boost the immune system and balance water in the body. Agate gemstones in general are believed to have a quiet energy associated with the heart chakra. Tree agate is also believed to boost the immune system and balance water in the body. Agate gemstones in general are believed to have a quiet energy associated with the heart chakra.