The polariscope is used to test cut or rough gemstones. Allows two polarising filters to observe the structure and optical properties of precious stones or minerals. It can also be used in identifying Moissanite and detecting strain in diamonds. It can be used with a thing called a stainless sphere, (that is a glass sphere with no strain lines in it,) or a loupe. It visually shows if a stone is doubly or singularly refractive and its optic sign. It will also show strain and twinning, which will occasionally help to distinguish between natural and man-made materials. Features: Heavy duty and precise testing Made with metal and optical glass Durable, reliable and made by professional craftsmen Gemologist tool for diagnosing optical properties of a gemstone (singly refractive or double refractive) Specifications: Size: Length : 80mm Diameter: 28mm Power for flashlight: AA battery x 2 (Batteries are not included) Material: Optics glass, Metal Set Includes: 1 x Handheld Polariscope 1 x LED Flashlight Carry Pouch