North Jetty Ocean Shores, Washington State

This twinned olivine crystal in showing two pleochroic colors. The twinning is at nearly right angles to one another. The single linear polarizer is oriented north/south.

Transmitted Darkfield Single Linear Polarizer Oriented N/S

This is a demonstration of the near match of refractive index for the olivines in the 1.704 refractive index mounting medium.