notes:  This item features a piece of cut and polished Virgin Valley petrified wood.  Common opal was the petrifaction mineral rather than the more common agate or jasper that you usually see in petrified wood.  It's pretty gemmy - translucent too.  I didn't get it measured or weighed prior to setting so you're looking at the size and weight of the stone plus the setting.  The display chain is not included.