Rock Candy Collection from Petit Bijoux. These very pretty natural amethysts and quartz stud earrings feature multi-faceted pear, oval and marquise shaped stones. The unique shape of these stones enhances the deep, rich colour and beauty of these stunning earrings. Claw set in sterling silver with posts and butterfly backs. These cluster style stud earrings measure approximately 15mm x 17mm in size and are perfect from day to night.