Ametrine Quality Factors

The best ametrines show distinct areas of orangy yellow and purple. These colors are featured in this graceful cut design. Photo by Lydia Dyer, © John Dyer & Co., gem courtesy John Dyer & Co.
The best ametrines show distinct areas of orangy yellow and purple. These colors are featured in this graceful cut design. Photo by Lydia Dyer, © John Dyer & Co., gem courtesy John Dyer & Co.
When Bolivia’s ametrine mine reopened in the 1960s after being lost for centuries, the gem’s bicolor appearance became popular with dealers and gem designers. Its colors range from pale to intense amethyst and citrine shades.

The rough output from the Anahi mine produces amethyst, citrine, and ametrine finished gems in a range of tone and color intensities. Photo © GIA and Tino Hammid.
The rough output from the Anahi mine produces amethyst, citrine, and ametrine finished
gems in a range of tone and color intensities. Photo © GIA and Tino Hammid.
Color
Fine ametrine shows medium dark to moderately strong orange, and vivid to strong purple or violetish purple. Larger gems, usually those over five carats, tend to show the most intensely saturated hues. Dealers look for an attractive half-and-half distribution of each color, with a sharp boundary between the two colors at the center of the fashioned gemstone.

Rectangular cuts show off ametrine’s unique appearance. Photo by Robert Weldon/GIA, courtesy Cynthia Renee Co.
Rectangular cuts show off ametrine’s unique appearance. Photo by Robert Weldon/GIA, courtesy Cynthia Renee Co.
Cut
Connoisseurs prize imaginative designer cuts that display ametrine’s two colors in artfully blended or contrasting combinations.

Dazzling Designer Cut
This 48.50-ct. ametrine, fashioned by gem designer Dalan Hargrave, dazzles the eye. Photo by Robert Weldon/GIA, courtesy Minerales y Metales del Oriente, Bolivia, SA.
Clarity
Much of the faceted ametrine in the market is eye-clean, meaning it lacks eye-visible inclusions.

Rectangular Step Cut
Like most faceted ametrine, this bicolor rectangular step cut has no eye-visible inclusions. Photo by Van Rossen, © ICA, courtesy Columbia Gem House.
Carat Weight
When it comes to highly prized ametrine, size matters. That’s because the best, most intense citrine and amethyst colors are found in larger sizes, usually over 5 carats.

This 87.66-ct. ametrine displays the rich purple of amethyst along with the contrasting orangy yellow of citrine. Photo by Robert Weldon/GIA, Courtesy Minerales y Metales del Oriente, Bolivia, SA.
This 87.66-ct. ametrine displays the rich purple of amethyst along with the contrasting orangy yellow of citrine. Photo by Robert Weldon/GIA, courtesy Minerales y Metales del Oriente, Bolivia, SA.