Amethyst is the purple variety of quartz, one of the most common minerals on Earth, colored by traces of iron combined with natural irradiation. For most of history amethyst was as valuable as ruby and emerald and was reserved for royalty and clergy. Then large deposits were discovered in Brazil and Uruguay in the 19th century, prices fell, and amethyst became what it is today: a beautiful, durable, widely available gem and one of the best values in the gem world.
Color and quality
Amethyst ranges from pale lilac to a deep, saturated purple, sometimes with flashes of red or blue. The finest material, historically called "Siberian," is a rich reddish purple with even color. Because amethyst is abundant, you can hold out for excellent color and clarity without paying rare-gem prices, and large clean stones remain affordable, which makes amethyst a favorite for bold statement jewelry.
Durable, with one caveat
At Mohs 7, amethyst is hard enough to resist scratching from everyday dust and is well suited to rings, pendants, and daily wear. It has no cleavage and reasonable toughness. There is, however, one thing to know: amethyst can fade with prolonged exposure to strong sunlight, UV, or heat. It is not fragile, but you should avoid leaving it in a sunny window for years or subjecting it to high heat, which can lighten the color permanently.
Amethyst, citrine, and ametrine
Amethyst has an interesting relationship with other quartz gems:
- Heat turns most amethyst yellow or orange, and the majority of commercial citrine is in fact heat-treated amethyst. Certain material heats to a green "prasiolite."
- Ametrine is a natural bicolor of amethyst and citrine in a single crystal, produced mainly in Bolivia, where zones of purple and yellow meet.
A note on synthetics
Synthetic amethyst (grown hydrothermally) is chemically identical to natural amethyst and can be very difficult to distinguish, even for experts, without laboratory testing. Because natural amethyst is inexpensive, this is more a matter of accurate disclosure than of large sums, but reputable sellers should still tell you which you are buying.
Caring for amethyst
Amethyst is easy to care for. Warm water with mild soap and a soft brush cleans it well. Ultrasonic cleaners are generally safe for untreated amethyst, though it is wise to avoid them if a stone might be fracture-filled or dyed. The main rule is simple: keep it out of prolonged intense sunlight and high heat to preserve its color.
Amethyst is a gemologist's favorite for a reason. It gives you rich royal color, real durability, and generous size, all at a friendly price, so long as you keep it out of the harsh sun.
