Quartz · February birthstone
Amethyst
Royal purple quartz, once as costly as ruby, now generous and affordable.
- Hardness
- Mohs 7
- Toughness
- Good
- Daily wear
- Good for daily wear
- Price tier
- USD 10 to 100 per carat, fine quality
- Colours
- Purple, Violet, Rose de France (pale)
- Origins
- Brazil, Uruguay, Zambia, Bolivia
Amethyst is purple quartz coloured by iron and irradiation in the earth. Until Brazilian deposits were found in the nineteenth century it ranked with ruby and sapphire; today it is abundant, which makes deep, saturated stones in large sizes an extraordinary value. The finest colour, called Siberian, is deep purple with red and blue flashes.
How to buy amethyst
Pay for saturation and evenness of colour; pale and zoned stones are common. Buy from sellers who state natural origin, since synthetic amethyst is widespread and hard to tell apart.
Treatments
Usually none; some pale stones are heated (which makes citrine); synthetic amethyst is common.
Care
Warm soapy water; ultrasonic is safe. Keep out of prolonged strong sunlight, which fades the colour over years.
Lore
The Greeks believed it prevented drunkenness; the name means not intoxicated. Bishops’ rings are traditionally amethyst.
