Amethyst is the most precious member of the quartz family. This gemstone is extremely popular for jewellery because of its regal colour, variety of sizes and shapes, affordability and wide range of hues.
The finest and most valuable amethysts are very clear, with very deep colour. It exhibits colours ranging from pale lilac to deep purple.
Amethyst is sometimes heat treated to deepen the colour, or to transform it into Citrine. Some forms of Amethyst may also change to a light green color upon heat treatment, and such stones are known as Green Amethyst within the gem trade.
Amethyst is generally more expensive than Citrine, its quartz cousin. Occasionally, Mother Nature combines the colours of Amethyst and Citrine into a single gemstone called "Ametrine". Like all quartz gems, Amethyst is relatively plentiful and is available in a wide range of sizes and shapes, including very large sizes.