← All tools
Gemological tool

Polariscope

Determines single vs. double refraction, quick and conclusive

Typical price$ 100 - 400
PortabilityLow portability
Field noteDesktop instrument

How to use it

  1. Place the stone between the two polarizing filters on the stage
  2. Rotate the stone slowly through a full 360°
  3. Singly refractive: stays uniformly dark throughout rotation
  4. Doubly refractive: alternates between light and dark four times per rotation
  5. Test from multiple orientations if result is unclear