Man Moon Necklace Mystery Stone Bead Vintage

Well it's not often that I do not know precisely what something is but this time I don't. It is a greenish stone - perhaps labradorite. There are are fractures within the stone that reflect light. It is old stock from my Excalibur days so after 30 years I simply don't remember. It measures 3/4's of an inch across. Carved face - bead hole runs thru the top of the head side to side. On the backside bottom it is flat so it sits on a table flat. It's on a simple black silk cord - just an old vintage item