I used a precious opal with a lot of play-of-color that is clearly visible to the naked eye. ^_^ Materials: Natural Stone - Precious Opal: 4-6mm Earring Fittings: 14kgf Chain: 14kgf Wire: 14kgf *Please be careful if you are concerned about allergies. *If you are concerned about inclusions or chips unique to natural stones, please refrain from purchasing. *Each item will be carefully packaged and delivered to the customer. *I have used opals with as much play-of-color as possible. *Please note that the color and shape may differ due to the camera. *This is the last one.