“The best color in the whole world is the one that looks good on you.” — Gabrielle Bonheur ‘Coco’ Chanel (1883-1971)

As I wrote a few months back when I described Five Gems that Capture My Imagination, I'm particularly drawn to vibrant stones with unusual properties. I love moonstone’s ethereal adularescence, the soft rainbow shimmer of pearl, and the shifting colors of alexandrite.

If you've been reading along with me, it's clear that my favorite gems almost all display more than one color. But I haven’t yet described one of the most delightful properties of multicolor stones: pleochroism.

Enigmatic and Haunting

The term pleochroism comes from the Greek words "pleo," meaning many, and "chros," meaning color. These enigmatic stones are the chameleons of the mineral world and can display prominent shifts in color when viewed from different directions.

This shift in color is revealed not only through light reflected back from the stone's surface, but also through light that passes through the stone. This is because pleochroic crystals are able to absorb different colors of light depending on how their internal crystalline structure interacts with the wavelengths of light that pass through them.

The result of this interaction of structure and light is that a pleochroic gemstone may display a dramatic shift in hue. For example, the stone may appear blue when viewed at one angle and green at another.

Unheated tanzanite pear pair from Tanzania

A Spectrum of Gemstones

In addition to being beautiful, pleochroism can also be a useful tool in gemology for stone identification, since the colors visible at different angles can aid in identification of the crystalline structure of a gemstone and thus help to classify it.

Rarity and Skill
While many minerals may be classified as pleochroic, true pleochroism is only discernible in translucent, gemstone-quality crystals, making them very rare. Gemstones such as agate, fluorite, liddicoatite, tourmaline, and tanzanite often display pleochroism to varying degrees and are favorites for those seeking this shift of color. 

 East West ring featuring Namibian tourmaline by Thesis Gems

Bring Pleochroic Gemstones to Life

Unlike alexandrite which displays color change under different light sources, pleochroic stones can visibly shift color in just an instant as their wearer moves. I think pleochroic stones truly come alive only when worn, as they catch the light and shift in color to mysterious effect. These stones are meant to be lived with, and their unique qualities make them a prized addition to any jewelry lover's collection.

If you're interested in adding a unique color-shifting stone like tourmaline or tanzanite to your collection, please reach out today. I'd be thrilled to share my love for these alluring gems and help you choose or design a piece to inspire you for years to come.