Onyx has a calming effect, which can be used to balance the hyper cray or cool down a hot-head. Onyx has been known to provide strength and support in times of mental or physical stress as well as instil self-confidence to it's wearer.
Lava rock is one of the oldest and most abundant minerals on earth, it is a very grounding rock, and deepens our connection to mother nature. It provides strength and courage to those who wear it, and provides guidance and understanding in situations where we may need to "bounce back". A calming stone, it is very useful in dissipating anger. You can put essential oils on them.