The main factor to take into account when valuing an Amethyst is color: the more intense the hue, the higher the value. The most desirable Amethysts display hues ranging from medium to dark, transparent and pure violet in color, without shades of red or blue, although blue or red streaks are desirable and highly sought after. Amethyst crystals contain few inclusions; none are usually visible when the gemstone is viewed with the naked eye from a distance of 15 cm. As the gemstone is popular with gemstone cutters and jewelers, Amethysts may be found in every cut imaginable, more than any other gemstone. Regardless of cut, color tones and high brilliance are the criteria that define a quality stone.
Varieties of Amethyst
In order to distinguish between varieties of Amethyst, in addition to color, the origin of the gemstone is often used and is synonymous with quality in some cases. Breijnho Amethyst, for example, is extracted in Brazil from the Breijnho mines and is particularly sought after for the purple streaks that appear on the intense violet surface. In contrast, Zambian Amethyst has a clear, royal purple color with beautiful shades of blue and red which illuminate the body with every movement. The rare Uruguayan Amethyst displays fascinating deep violet hues and characteristic red streaks. The Rio Grande Green Amethyst (Prasiolite) displays intense green hues and is usually the most desired of the traditional Green Amethysts; these two varieties are delved in different mines: Green Amethysts are found in Uberaba (Minas Gerias), while Rio Grande Green Amethysts are sourced from Rio Grande do Sul.
Green Amethyst: cut gemstone and raw crystal
The following varieties of Amethyst are classified based on color: Platinum Amethyst is named for its optical similarities with platinum, thanks to silvery streaks. Brazilian examples of Lavender or Rose de France Amethyst display clear, delicate pastel purple hues. The Bicolor Amethyst is a composite of Amethyst and White Quartz, formed by the fusion of the crystals due to changing environmental conditions. Another bicolor variety is Ametrine (found in the Anahi mine in Bolivia see Ametrine), composed of Citrine and Amethyst, and introduced into the market in 1980.