This is a vintage sterling charm of a Celtic cross. I am not sure whether the green is enamel or malachite. It is unmarked sterling, was made by Mizpah in England, and was rhodium plated to prevent tarnishing. It measures just over one inch high and just over 5/8 of an inch at its widest and weighs 1.5 grams.
All the charms that I sell are vintage, and may show signs of wear.