What Gems Are Trichroic?

Trichroic gems show three colours. Tanzanite & Iolite are examples of a trichroic gems. Tanzanite was only discovered in 1967. It has a striking blue/violet colour although there is a 3^rd colour of yellow/brown.

Is Tanzanite a Trichroic?

Tanzanite is a trichroic gemstone. This means that Tanzanite's chemical structure causes the double refraction of white light as it passes through it.

What is dichroic and Trichroic minerals?

Tetragonal, trigonal, and hexagonal minerals can only show two colors and are called dichroic. Orthorhombic, monoclinic, and triclinic crystals can show three and are trichroic. ... Gems are sometimes cut and set either to display pleochroism or to hide it, depending on the colors and their attractiveness.