Discovered in 1960, tugtupites are relatively recent entries into the gem world. A member of the helvine mineral group, tugtupite is also closely related to sodalite.
You may find this mineral referred to as “Reindeer Stone,” after the type locality. Tugtup means “reindeer” in the Greenlandic Inuit language. (Perhaps the gem’s similarity to a certain famous reindeer’s nose has also reinforced that moniker).
Do Tugtupites Glow in the Dark?
This gemstone displays striking phosphorescence and tenebrescence. Exposure to ultraviolet (UV) light, whether from artificial sources or sunlight, intensifies its colors, generally making it darker and redder. X-rays also darken paler colors. On the other hand, darkness will cause its red colors to fade. These effects are reversible.
Tugtupites can even glow in the dark after UV exposure. See “Identifying Characteristics” for more more information.
The hardness of tugtupites can range from 4 to 6.5. On the softer end, a knife could scratch one. On the harder end, a specimen could exceed the hardness of more commonly encountered jewelry stones, such as feldspars. However, their distinct cleavage makes these stones better suited for pendants and earrings. Protective settings are recommended for ring use. Of course, owners should be aware of this stone’s sensitivity to UV and darkness.
Moving beyond a mineral collection, these gems could make interesting Christmas jewelry pieces or glow-in-the-dark fashion statements. However, tugtupite’s abundance has declined in the years since its discovery. Thus, it’s become somewhat hard to obtain, especially in cuttable pieces.
Faceted pieces are extremely rare. Tugtupites are more typically cut into cabochons.
Very distinctive rose-red color. Generally redder in shortwave (SW) than longwave (LW).
Taseq, Greenland: SW, pastel orange-red; LW, bright orange: phosphoresces bright cream or orange-cream, better reaction in SW than LW.
Kvanefield, Greenland: LW, bright orange to orange- red; SW, cerise red, and very intense; phosphoresces dull red to medium cream white.
The material darkens in color when exposed to UV light and slowly bleaches.
A tugtupite and quartz piece under normal light, then exposed to ultraviolet light. Kvanefjeld plateau, Qeqertaussaq Island, Kangerdluarssuq Firth, Ilimaussaq complex, Narsaq, Kitaa (West Greenland) Province, Greenland. Photos by Géry Parent. Licensed under CC By-ND 2.0. (Slide show created to highlight fluorescence).
If placed under pressure, tugtupite can generate an electrical charge.
Almost all gem-quality material comes from the Taseq and Kvaneﬁeld areas of Tugtup, Ilimaussaq, Greenland.
There are only two other known sources of this rare mineral:
Mont Saint-Hilaire, Quebec, Canada.
Kola Peninsula, Russia.
Gem cutters have only faceted a few gems, all very small and none completely transparent. Typical gem size ranges from 1 to 2 carats. While cutters can facet translucent material, they usually cab such pieces. After the initial discovery, gem carvers made decorative objects from some of the larger tugtupites.