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| Hackmanite from Kola Peninsula |
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More Hackmanite on ebay auction. See also Sodalite. |
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Hackmanite en.wikipedia.org Hackmanite is an important variety of sodalite exhibiting tenebrescence: when freshly quarried, it is a violet to red colour and gradually fades to a white or green in sunlight. If left in a dark environment for some time, the violet will return. The process is accelerated by the use of shortwave ultraviolet light. Much sodalite will also fluoresce a patchy orange under UV light. http://www.free-form.ch Sodalite that shows this behavior has been given the variety name hackmanite. Since the pink color is quickly bleached by light, it is an unstable color in this mineral. That certain minerals can, without change of essential composition, lose or gain color when exposed to light is well known. Leaving the specimen in the dark from a few hours to several weeks may restore the pink color of hackmanite. Exposure to short- or long-wave ultraviolet will also restore color. Short-wave ultraviolet is the most effective for this purpose. The speed with which this is accomplished and the depth of color achieved varies from specimen to specimen.... |
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