Brazil, 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, Yellow, Orange, India
Not Available, Southern and central Africa
Yellow
Brown, White, Greenish, gray, Green, Brownish
SiO2
(Mg,Fe2+ ) 2(Mg,Fe2+ ) 5Si 8O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)