For the best ammolite buying experience, learn about this unique gem’s quality factors.

Ammolite Buying and the Four Cs

Although ammolite grading differs from other colored gemstones, the Four Cs still prove useful for understanding ammolite quality.

The IGS ammolite value listing has price guidelines for ammolite naturals, doublets, and triplets.

Color

Color is the most important factor in ammolite quality. Higher quality ammolite exhibits more, brighter colors, greater iridescence, shifting color with different viewing angles, and color regardless of the gem’s rotation.

Number and Rarity of Colors

Ammolite can display any color of the rainbow, but specimens that display three or more colors are the most desirable.

Red and green hues are common, while blue, violet, gold, and crimson are rare.

Iridescence

Ammolite’s unique structure allows for beautiful iridescence. In this gem, tiny aragonite crystals align in a plate-like structure whose thickness is near the wavelength of white light. Because of this, a mesmerizing play of color appears in the stone. Ammolite with greater iridescence will have more value.

Chromatic Shift

As a piece of ammolite rotates, an observer can witness changing colors. Lower-quality ammolite is monochromatic, meaning a slight change, perhaps from a lime green to a…