Polariscope Guide, Part 2: Testing For Optic Figure and Sign
Step 3: Practical Gemology
Table of Contents
Testing for optic figure and sign is an important technique for gemstone identification. You’ll need a polariscope and a condensing sphere. If your polariscope doesn’t have built-in magnification, you’ll also need a hand-held or head-mounted magnifier.
Finding Interference Colors
Begin by setting the polariscope filters …