Amethyst is a violet to purple variety of quartz, colored by trace amounts of iron and natural irradiation within the crystal lattice. As one of the most historically recognized colored gemstones, amethyst has been used for ornamental, ceremonial, and gemological purposes for centuries. Its mineralogical classification, formation process, and relationship to other quartz varieties are documented within the broader context of the gemstone family in the Gemstone Encyclopedia.
Natural amethyst is sourced from a wide range of global deposits, with notable occurrences in Brazil, Uruguay, Zambia, Madagascar, and parts of Eastern Europe. Differences in geological conditions contribute to variations in hue, saturation, crystal clarity, and crystal size. The influence of geographic origin on gemstone appearance and availability is further explored in the context of rarity and provenance in Gemstone Origins & Rarity.
Quality evaluation of amethyst primarily focuses on color purity, saturation, tonal balance, and transparency. Deep, evenly distributed purple hues with secondary red or blue modifiers are generally considered more desirable than pale or uneven coloration. Unlike many rare gemstones, amethyst is widely available, and value is driven more by aesthetic quality than by scarcity. Factors influencing color perception and grading are discussed in detail in Understanding Gemstone Color.
Amethyst is typically not treated, though heat treatment may occasionally be used to alter color or produce citrine. Disclosure of treatment status remains an important part of transparent gemological practice. The distinction between natural, untreated stones and those subjected to enhancement is explained in Treated vs. Untreated Gemstones.
With a Mohs hardness of 7, amethyst is suitable for use in a wide range of jewelry applications, including rings, pendants, and earrings, provided standard wear considerations are respected. Practical guidance on selecting gemstones for jewelry settings and durability requirements is outlined in the Jewelry & Gold Guide – How to Choose Gemstone Jewelry.