The Gem-N-Eye III digital handheld refractometer measures reflectivity of faceted gems, then applies internal algorithms to calculate refractive index and suggest or confirm gemstone-identity without the use of toxic fluids. Gives a digital readout of RI to 3 places (accurate to .010), along with names of matching gems drawn from its internal 200-gem database (no other computer required). Also measures gems above 1.81 RI so you can distinguish diamond from CZ and moissanite as well as read high zircon, garnets and more. Operates on battery or AC adapter and includes a handy travel case. One year warranty.