Sometimes amethyst and citrine colours are found in the same crystal of quartz. These bicolour yellow and purple quartz gemstones are called ametrine.
Ametrine is most typically faceted in a rectangular shape with a 50/50 pairing of amethyst and citrine. Sometimes a checkerboard pattern of facets is added to the top to increase light reflection. Ametrine can also be cut to blend the two colours so that the result is a mixture of yellow, purple, and peach tones throughout the stone.
