Ametrine

Ametrine is the only major gemstone that carries two quartz varieties in one crystal: amethyst purple on one side, citrine gold on the other, divided by a boundary that formed in the ground rather than in a workshop. Commercially, the story is even narrower than tanzanite's. Virtually all natural ametrine comes from a single source, the Anahi mine in eastern Bolivia. What creates the color zones is explained in What Is Ametrine?

The stones in this collection are untreated as standard. That statement matters here more than in most quartz, because the wider market also carries heated and synthetic bicolor material sold under the same name. A natural ametrine shows its two colors in distinct zones with a boundary the cutter chose to display; each of our listings states treatment status plainly. The wider context is covered in What Is a Natural Gemstone?

Evaluation is unlike single-color stones. The prize is balance: both zones saturated, neither washing the other out, and a boundary crisp enough to read across the table of the stone. Cutters orient every ametrine as a compromise between color split and total brilliance, which is why rectangular and fancy cuts dominate the fine end of the material, a choice explored in Understanding Gemstone Color.

At 7 on the Mohs scale, ametrine wears well in rings, pendants, and earrings. Every stone ships with the Sosna Gems Colored Stone Report, our internal documentation, and independent laboratory certification can be arranged on request.

Larger ametrines remain one of the quieter opportunities in colored stones: single-source supply, natural bicolor, and prices that have not yet caught up with the story. For a stone set into a commissioned piece, see bespoke jewelry.