Mimetite is a popular mineral among collectors, and is a lead arsenate mineral. It is usually found in the oxidised zone of lead ore deposits, and occurs a variety of habits including flat tabular hexagonal crystals, long prismatic hexagonal crystals, rounded crystals, and even some that look fibrous! However, not all mimetite-looking crystals are mimetite. It can be difficult to distinguish them visually from pyromorphite or vanadinite.
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And the colour range, well, wow! It can be colourless, white, and various shades of yellow, orange, red, brown and green. A wide variety to be sure. Sometimes, crystals are even colour-zoned.
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Excellent specimens of this mineral have been found in Tsumeb, Namibia; the Ojuela Mine, Mapimí, Mexico; the Rowley Mine in Arizona, and from the Guatomo Mine (‘Hat Yai’ mimetite locality), Thailand. But these are just a few localities…
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In Cumbria, England, there is an unusual habit known as “campylite”. These are very distinctive with most specimens from this area have orange to brown rounded barrel-shaped crystals.
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In Australia, the best localities are Mount Bonnie in the Northern Territory; Broken Hill; the Elura Mine in New South Wales; and the Magnet Mine in Tasmania.
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So if you don’t have mimetite specimens in your collection, you should seriously think about it!
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Find out more about this popular mineral on Mindat.org.
And don’t forget to check out other mineral entries here!