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Anyone Can Own Ametrine
If you search online or go to a jewelry store that has a nice selection of colored stone jewelry, you might find a few pieces of ametrine for sale. The price is usually inexpensive when compared to other stones of similar size and beauty – certainly less expensive than bicolor tourmaline. Almost anyone who can…
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Synthetic / Treatment-Created “Ametrine”
Laboratory experiments in 1981 determined that heat and irradiation can be used to convert natural amethyst into a bicolor material that has an appearance similar to natural ametrine. This process is costly to do well and is not known to have produced a significant amount of treatment-created “ametrine.” In 1994 a laboratory in Russia began…
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Ametrine Gemstones
A crystal containing both amethyst and citrine in contact with one another can be called “ametrine.” These crystals usually contain zones of clear quartz, amethyst, and citrine. When these crystals are cut into pieces that are appropriately sized for faceting gemstones, only a portion of the stones will be ametrine. The remainder will be amethyst,…
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History of Ametrine
According to legend, the Ayoreo Indian tribe of eastern Bolivia knew about the bicolor quartz crystals over 500 years ago. Perhaps the earliest formal documentation of natural quartz crystals with zonal coloring of purple and yellow is in a 1925 issue of American Mineralogist. These were basal sections of quartz crystals with color sectors alternating…
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What Gives Ametrine Its Color?
The colors of amethyst and citrine are produced by iron impurities with different oxidation states within the quartz. Purple is thought to be produced by Fe3+ that is oxidized to Fe4+ by natural radiation emitted by the decay of potassium-40 in nearby rocks. The golden-yellow is thought to be produced by Fe3+. If a well-formed ametrine crystal…
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Where is Ametrine Produced?
Ametrine is rarely found in nature. Almost all of the world’s commercial ametrine production has been from the Anahi Mine in southeastern Bolivia. The mine has been operated by Minerales y Metales del Oriente S.R.L. since 1989. The Anahi Mine is in a dolomitic limestone of the Murcielago Group, a sequence of limestones up to 1500 feet…
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What is Ametrine?
Most people have never heard of ametrine and are very surprised to see purple and yellow in a single transparent gemstone. Ametrine is a rare gemstone with a finite supply that is produced in commercial quantities at only one mine in the world. It is a relative newcomer to the gemstone trade, being available in…