You are looking at a labradorite skull pendant.

Subtle green/blue/yellow/etc. metallic iridescent. Brings forth each person's strengths to share with the world. Originality. Easier, more restful sleep. Helps us relate to others. Opens energy flow to Solar plexus and Brow Chakra and whatever other centers are most in need. Still evolving along with us. Fragile, avoid salt cleansing.