... most precious gems. The RHG-181, commonly known as Gemstone Refractometer, is the primary and most powerful tool in identify and ... - Polarizing Filter- 3 pieces 1.5V AG13 Batteries- Carrying Case- Refractometer Index Reference List (For 77 common gemstones, i.e. Calcite ... , Jadeite, Quartz etc.)- User's Manual RHG-181 Gem Refractometer w/ Built-in Light Source + RI Oil