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.
|
USSINGITE,
Kola, Russia
L 2,5 x H 3 cm
|
| UV
longs / long-wave |
| collection
et photographie © Patrick
Arweiler |
|
|
