Digital refractometer by Presidium (model Prim II) Digital scales - regular lines - resolution 0.001g Disadvantages over an optical refractometer:-

Disadvantages over an optical refractometer:- it's not as versatile as an optical refractometer

Can be used anywhere

or it can be disabled

You will see the discount by each item when you click View Basket

brilliant cut (round) only

Digital refractometer by Presidium (model Prim II) Digital scales - regular lines - resolution 0.001g Disadvantages over an optical refractometer:-Summary Made by Presidium, the leading manufacturers of gem testing equipment. There is downloadable software to connect it to your computer. The reading is then displayed along with a list of stones that match the reading, and you can click on each stone to see more information (constants). This saves time looking up charts. Comes with a USB cable (connects to any computer mobile device USB mains adaptor). Works with loose stones and also stones