3. XPL using orthoscopic illumination

Observations with the polariser and analyser

We can observe phenomena linked to birefringence and the position of the optic indicatrix which are related to the form of the crystals.

By working without the condenser incorporated (orthoscopic illumination) you can study:

the interference colour,

the extinction angle,

the sign of elongation,

twinning.

zoning.

Index | Introduction | PPL