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, flashes of red or blue. Without Amethyst crystals contain few inclusions; none are usually visible when the gemstone is viewed with the naked eye from a distance of 15 cm.Varieties of Amethyst - The finest amethyst come from Uruguay, Siberia (primarily mined out) and the 4 Peaks mine in the United States. (Mined out of significant stones). Africa is producing amethyst but only Uruguay still has “Siberian quality,” gems. Meaning deep purple with a blue undertone and red flashes.