Opal, 14 karat yellow gold pin-Fire Opals, 14 karat yellow gold pin-necklace drop. 4.2 grams of gold measuring 1-1/2 inches in length Opal (9) round rich colored deep bluish, fire opals are set in an open design. This item is a pin but can also be used with a chain to hang as a pendant.GIA gemologist inspected and evaluated necklace drop. 4.2 grams of gold. Opal (9) round rich colored deep blue fire opals