Ussingite
Ussingite is found in three localities - Kola Peninsula, Russia, Mt. St Hilaire, Canada, and the Ilimaussaq Complex, southern Greenland. It is usually found in a fine-grained massive form, is somewhat brittle and the hardness H=6.0 to 7.0. Transparent to translucent the color can range from pale pink, lilac-blue to a dark violet red. The streak is white and luster is slightly greasy to vitreous; pearly on cleavage planes.
Ussingite is a secondary mineral in pegmatites associated with sodalite syenite. It is most often found associated with microcline, natrolite, aegirine, sodalite, and albite. It is found throughout the complex and varies in fluorescence from “not at all” to bright orange, dim green, or bright green. The greenish hues are the rarer varieties.
The specimen to the left is from the Ilimaussaq Complex, and fluoresces a bright green. Some pieces also exhibit the typical orange glow found in sodalite from the area. Interestingly, Ussingite from Russia is reported to FL a “sodalite orange” (see images below). Additional examples of ussingite specimens may be seen in the gallery below.
Ussingite may be used to cut beautiful cabochons - it takes a polish well.
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USSINGITE, Kola, Russia L 2,5 x H 3 cm |
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UV longs / long-wave
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collection et photographie © Patrick Arweiler
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