Ametrine Gemstone Beads

Frequently asked questions

• Where does ametrine come from?

  Ametrine comes from the Anahí Mine in the Santa Cruz department of eastern Bolivia, near the Brazilian border. The mine has been the dominant source since modern commercial production began in the 1970s and remains the only commercially significant deposit of natural ametrine. Material sold as ametrine from other origins is usually synthetic hydrothermal quartz or heat-treated amethyst-citrine, not geologically-formed bi-color material.
• Is ametrine natural or treated?

  Genuine Anahí ametrine is sold natural. The bi-color zoning between the amethyst purple and citrine yellow sectors is the result of differential iron oxidation during crystal growth — a mineralogical feature, not a treatment. Ametrine in Dakota's catalog is natural Bolivian material. Synthetic hydrothermal ametrine (most commonly Russian-grown) and heat-treated amethyst-citrine imitations exist in the broader market; treatment and origin should appear on the product page — ask before buying if either isn't specified.
• How does ametrine get its two colors?

  The two colors come from iron in two different oxidation states within the same quartz crystal. The amethyst sector contains iron in the ferric state (Fe³⁺), which produces the purple color when activated by natural radiation. The citrine sector contains iron in the ferrous state (Fe²⁺), which produces the yellow-to-golden color. The two sectors formed together because temperature gradients during the crystal's growth allowed both oxidation states to be present in different parts of the same crystal — an unusual geological condition that explains why the Anahí Mine is essentially the only natural source.
• What's the difference between ametrine, amethyst, and citrine?

  All three are color varieties of quartz, mineralogically identical except for the iron oxidation state. Amethyst is purple quartz (ferric iron); citrine is yellow-to-golden quartz (ferrous iron); ametrine is a single crystal that contains both — a visible boundary between an amethyst sector and a citrine sector within one stone. All three share quartz's Mohs 7 hardness and uncomplicated care profile.
• How durable is ametrine for daily wear?

  Mohs 7 — durable enough for any jewelry application, including rings, bracelets, and necklaces. Standard care: wipe with a soft cloth and mild soap. The one caution specific to ametrine is light and heat sensitivity: the citrine sector can fade with prolonged direct sunlight or sustained high heat. Avoid leaving ametrine jewelry on sunny windowsills or near heat sources for extended periods.