![]() ![]() ![]() When heating amethyst to 300-400☌, partial destabilization of the colour centres may cause the stone to turn a golden colour much like natural citrine, or in some cases the stone may turn a greenish colour resembling natural prasiolite depending on the trace element content of the amethyst. ![]() It is possible to treat amethyst because of the chemical basis for its colour. For this reason amethyst crystals should not be left in direct sunlight for long periods, and gemstone jewellery made with amethyst should not be worn when taking part in activities that involve spending large amounts of time in the sun. Exposure to UV radiation for extended periods of time unfortunately causes a destabilization of the FeO 4 colour centres and results in a loss of colour. ![]() Here are more of our favourite amethyst gemstones:ġ3.76ct Emerald Cut Amethyst Fantasy/Fancy Cut Pairīecause of the chemistry involved, the colour of amethyst is not stable under certain conditions. Such trends in the colouration of amethyst from different localities can sometimes be used to help narrow down where amethyst may have come from if its origin is unknown or high level laboratory test is unavailable. This is why one may see a striking difference in hue and tone when comparing amethyst from two different locations, such as the light magenta amethyst often found in Brazil and the deep indigo-violet amethyst found in Uruguay. These other elements are responsible for the wide range of colours that amethyst may display and the variation in hue that is seen in amethyst crystals from different localities, as the local geology would cause different combinations of trace elements to join the iron impurities within growing quartz. It is the combination of FeO 4 and other trace elements that truly brings out the colour of amethyst, as only a small amount of iron is required to produce the desired hues when the correct mixture of other elements is present. This colour centre is responsible for the violet base colour seen in amethyst, but small amounts of other elements contribute to the gemstone’s hue. The radiation exposure causes the iron ions to lose an additional electron and become Fe 4+ ions, which then combine with oxygen to form an FeO 4 colour centre. The colour of amethyst primarily results from impurities of Fe 3+ ions within the quartz structure that have been exposed to gamma radiation and during formation at certain temperatures. Quartz often acquires colour during formation when metals and other elements get trapped inside the growing crystal. Today notable sources of amethyst include Brazil, Uruguay, Bolivia, Mexico, Canada, Russia, Austria, Zambia, and India. Lighter colours of amethyst are generally considered to be less valuable, but amethyst of a light lavender tone referred to as “rose de France” has recently become more popular for use in gemstone jewellery. Deep rich purples with a greater proportion of blue-indigo tones than red are considered ideal, with the most valuable colour being known as “Siberian purple” or “Russian purple” in reference to amethyst of this colour that was once mined in Russia. This stone can display a multitude of different hues, with a range that includes pinkish-lavender, magenta, mauve, violet, purple, and indigo with the additional potential to exhibit faint tints of red and blue. Amethyst has long been important to human beings, and can be found in almost every country on Earth.Īmethyst is a variety of quartz characterized by its unique purple-violet colouration. Residing among the most recognizable and most well known of all gems, this gorgeous purple stone can be easily identified by people of all ages and walks of life. The colour of amethyst indisputably makes this gemstone one of the great treasures of the mineral realm and the most valuable single-colour variety of quartz. ![]()
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