Herkimer Diamond Stud Earrings -Sterling Silver-Genuine Herkimer Diamonds Sterling Silver prong setting approx. measurements a. 7. 3mm x 4mm & 7mm x 4. 3mm b. 6mm x 4. 7mm & 6. 2mm x 4. 8mm c. 7. 4mm x 5mm & 7. 4mm x 5mm d. 4. 1mm x 2. 8mm & 4mm x 2. 8mm *Herkimer Diamonds are double terminated quartz crystal. They are known as one of the most powerful of all quartz crystals and often used in meditations. They act as powerful amplifiers when you are using them with other gemstones. Herkimer