Iolite possesses two distinctive features—a beautiful, violetish blue through slightly violetish blue hue derived from iron and a striking, eye-visible pleochroism. Its pleochroic colors differ with ...

This gem material exhibits unique optical and physical properties that include a wide range of saturated body colors, aventurescence, and strong pleochroism. The feldspar is An 70 labradorite, a high ...

In this field of view coarse grained cassiterite shows beautiful red-brown pleochroism and some sector zoning. The groundmass is predominantly muscovite that crosscuts the cassiterite with a later ...