Gold, Silver, Platinum Jewelry Testing Stone
Measuring at 8″ x 2″ x 3/4″, this large natural testing stone helps you to determine the karat value of Gold jewelry Silver jewelry and platinum jewelry. This is to be used with 10k testing acid solutions,  14k testing acid solutions,  18k testing acid solutions,  22k testing acid solutions,  Silver testing acid solutions and Platinum testing acid solutions. The stone comes in a wooden storage box as shown in the photo. A must for metal recyclers, brokers, antique buyers and collectors alike.