These names describe colours of natural Quartz (purple, yellow and a mixture of both). Their deep, highly saturated hues and, often, a total lack of inclusions makes them perfect for your jewellery pieces!
Natural Citrine is quite rare and is usually made by treating Amethyst to change the stone’s colour from purple to yellow. The rarest of all Quartz is known as Ametrine, which has zones of both purple Amethyst and yellow Citrine, and is mined only in one place in Bolivia. The majority of Ametrine on the market today is created by the treatment described above.
Because of the nature of Amethyst and the Quartz family of stones, synthetic stones of this type are very rare and do not frequently find their way into the supply chain.