Frequently asked questions

• Is natural ametrine actually one stone, or is it two stones glued together?

  Natural ametrine is a single quartz crystal that contains both amethyst (purple) and citrine (golden-yellow) zones in the same piece. The color split happens because iron impurities in different parts of the crystal experienced different temperature and irradiation conditions during formation, producing two color centers within one continuous structure. It is not bonded, doublet, or composite material. When you see a sharp color boundary in a bead, that's the natural growth zone preserved through cutting. Treatment status should be disclosed — if it isn't specified, ask before buying.
• Why does almost all commercial ametrine come from Bolivia?

  The Anahí mine in eastern Bolivia is the dominant commercial source for natural ametrine and has been since the 1970s. The specific geological conditions that produce stable bi-color quartz in gem-cuttable sizes are rare, and Bolivia is where those conditions occur at scale. Small amounts have been reported from Brazil and India, but Bolivian Anahí material accounts for the vast majority of what reaches the bead trade. Origin should be disclosed when known — ask before buying if it isn't specified.
• Why is ametrine mostly cut as pebbles and nuggets instead of calibrated rounds?

  Ametrine is valued for the visible color split between purple and gold, and free-form cuts (pebbles, nuggets, ovals) showcase that zoning far better than tight rounds. A faceted or polished nugget can present a clean amethyst-to-citrine transition across the face of the bead, while a small calibrated round may land entirely in one color zone and lose the bi-color effect. Rounds and chips do exist in the cut, but designers stringing for bi-color visibility usually reach for the larger free-form shapes.
• Will the amethyst half of an ametrine bead fade in sunlight?

  Amethyst color in quartz can fade with prolonged exposure to strong UV or direct sunlight, and the same is true for the amethyst portion of ametrine. Citrine is more stable. For finished pieces, this is rarely a practical issue with normal wear, but ametrine should not be stored in a sunny window or left on a dashboard. At Mohs 7 the stone itself is durable for most jewelry applications including rings, with mild soap, water, and a soft cloth for cleaning. Ultrasonic cleaning is generally safe on untreated material.
• What pairs well with ametrine in a design?

  Because ametrine already carries both ends of the quartz color range, it pairs naturally with solid amethyst or solid citrine to extend either side of the gradient, and with smoky quartz or clear rock crystal to bridge the tones. Metals: yellow gold and rose gold flatter the citrine zone; sterling and white gold lift the amethyst. For contrast accents, designers often reach for pyrite, garnet, or peridot. The bi-color zoning reads strongly at larger bead sizes and in free-form cuts, so it can carry a piece as the focal element with quieter spacer beads around it.