General
In 1957, European geologists discovered tugtupite in Greenland although the Greenlandic Inuit knew
this mineral since centuries. They named this red mineral according to the reindeer ("tuttu") blood.
Apart from Greenland, tugtupite has been found only in Canada (Mont St. Hilaire) and Russia (Lovozero Massif /
Kola Peninsula). Only Greenland can supply the market with sufficient quantities of worthy, sometimes deeply red and
highly demanded tugtupite. The finest stones are usually reserved for jewelry.
Deposits in Greenland
|
South Greenland |
|
Ilímaussaq Complex * |
Tugtupite occurs in alkali intrusive igneous rocks as vitreous, translucent (sometimes even transparent) masses
up to 10 cm across but usually one can find only small grains. Deposits are located within an area of 8 x 17 km
in south Greenland, called "Ilímaussaq Complex", home to over 250 different minerals (Greenland: over 500
minerals, type locality for 77 minerals). Here Tugtupite was found in 1957, at
Tugtup Agtakôrfia along the north
shore of the Tunuljarfik fjord which cuts through this nepheline-syenite intrusion. The small town Narsaq is
located 11 km west of the center of the complex. See
satellite image!
The area is scarcely covered with plants, very much weather-beaten and rising from SE to NW. Mount Ilímaussaq
(1390 m) is the highest point. The whole area can be reached only in summer, by foot. Collectors should rely on
experienced, trained leaders to cope with dangerous situations.
Color and Fluorescence
Color
|
Color Change * |
|
Tugtupite Vein * |
In daylight the tugtupite color ranges from white to pink or deep red. Even rare, blue ones do exist although they
are bleached by UV light after a while, and the blue color does not return. Alledgedly also green tugtupite shall
exists. The red color orginates from minor amounts of sulphur in the mineral. If a rather pale tugtupite is
exposed to sunlight or UV light its color noticeably deepens; in darkness the red fades into a paler red.
Tugtupites may show also a reaction when kept warm. Inuit say that some stones turn into a deeper red according to
the intensity of a romance.
Fluorescence
|
UV Fluorescence * |
Tugtupite is known for its superb fluorescence.
Often referred to as the "king of fluorescent minerals", it is known worldwide for its beauty under
ultraviolet light. When exposed to UV light (or sunlight) the color deepens, sometimes to an almost grape
color (a tenebrescent property). This color change can last for weeks, and is easily restored simply
by exposure to sunlight. Under SW UV it glows cherry-red, under LW UV the response is a more or less weaker orange.
Dark red tugtupite from the Kvanefjeld area shows the strongest UV response which can last for several weeks.
This tugtupite is not phosphorescent.
Pale pink tugtupite from the
Taseq area shows a different UV response:
a weaker red under SW UV, salmon-orange under LW UV and pinkish-lavender under midwave UV. This tugtupite
phosphoresces strongly white to cream.
To make the UV response even more complex, stones from other locations
of the Ilímaussaq Complex show a pinkish-orange under SW UV, a very bright white under mid-wave UV
and orange under LW UV, also phosphorescent.
Quality
Translucent or transparent, deep red (in daylight) stones from Kvanefjeld are used for jewelry (rings, necklaces etc.).
Inuit artisans raise their income by cutting the stones into cabochons, polishing them and selling them.
Better tugtupite stones are translucent and without any visible other material. The best stones are nearly
transparent and much sought after by gemstone enthusiasts although one has to consider the Mohs hardness of only 4.
* Photos by kind permission of
© www.minershop.com, Mark Cole who also
offers guided Mineral Geo Adventure Tours to the major sites within the Ilímaussaq Complex.
* Photos by kind permission of
© www.fourth-millennium.net, Corby Waste.
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