- Color: bi-color, violet / yellow
- Hardness: 7
- Refractive index: 1.54 - 1.55
- Density: 2.65 - 2.66
- Chemical composition: SiO2
- Crystal structure: hexagonal
- Lustre: vitreous
- Origins: Brazil, Bolivia, Uruguay.
Ametrine is a bi-color variety of quartz, formed by amethyst and citrine on opposite sides of a crystal. The best ametrines have intense colors and a distinct central border between the violet and yellow colors.