A Slender, Double Refractive, Crystal of Unknown Composition Causes a Beautiful Image When it's Host, a Garnet, is Placed in Between Crossed Polars. Image by Tim Spauwen.

A Slender, Double Refractive, Crystal of Unknown Composition Causes a Beautiful Image When it’s Host, a Garnet, is Placed in Between Crossed Polars.
Image by Tim Spauwen.