Gem Refractometer's primary use is to measure the angle at which light traveling through the stone is bent or refracted. The Gem Refractometer can also determine whether a stone is singly or doubly refractive. Flashlight included.

• Gem Refractometer's primary use is to measure the angle at which light traveling through the stone is bent or refracted. The Gem Refractometer can also determine whether a stone is singly or doubly refractive. Flashlight included.

Gem Refractometer's primary use is to measure the angle at which light traveling through the stone is bent or refracted. The Gem Refractometer can also determine whether a stone is singly or doubly refractive. Flashlight included.Unbranded