These earrings have lovely Andamooka Opal cabochons, also known as "Queen's Opal", set in sterling silver. This is a special type of opal where it has flecks of opal growing in shale rock. It has lovely contrast between the iridescent flecks and the gray-black host rock.
It has a French wire back to it which allows for easy on and off.
The stones are ~2cm x 1.5cm