Ametrine is the occurance of Amethyst and Citrine together in one gem. It is the purple/yellow variety of Quartz, one of the most common minerals on Earth. Ametrine is availablein a variety of colors, from violet/yellow to deep purple/orange. The color is due to trace elements added to the basic silicon dioxide formula. Natural Citrine gems can sometimes display both violet and yellow colors in striking zonal patterns corresponding to rhombohedral growth regions. Natural Ametrine is somewhat rare in nature but is often artificially created by heating both natural and synthetic Amethyst. These gems are virtually indistinguishable from natural Ametrine gems.
The main sources of Ametrine are Rio Grande do Sul, Brazil and La Gaiba District, Sandoval Province, Santa Cruz Department, Bolivia.