Optical Property · Reviewed definition

Pleochroism

Different body colors observed in some anisotropic materials when viewed along different crystallographic directions.[1]

Plain English

What it means

A pleochroic gem can show different colors as viewing direction changes.

Why it matters

The observation can support identification and guide cutting orientation.

What it does not tell you

Strength depends on material, color, orientation, and observation method.

Evidence

References

  1. 1
    Analysis of Gemstones at GIA Laboratories

    Gemological Institute of America

    Open source