has a bright Marquise cut Mexican Fire Opal 4ct and a lot of Round cut White Swarovski crystals aroud the opal, they are measured 2.2ct. That is total 6.2ct for whole setting. Amazing clarity and shimmering facets. The item is plated with 18K white gold, it will not tarnish or wear off with normal use. The whole setting of pendant measured 15mm width x 27mm length. The necklace is in regular 18 inches.