Gem collectors prize tugtupite for its rich colors and intense reaction to ultraviolet light. Sporadically used in jewelry, clean, faceted tugtupites are great rarities.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Crystallography||Tetragonal. Only occurs in massive and compact form.|
|Colors||White to pink, rose red, greenish; mottled. Rarely, light blue.|
|Luster||Vitreous to greasy.|
|Birefringence||0.006 - 0.008.|
|Luminescence||Very distinctive rose-red color. Generally redder in SW than LW. See "Identifying Characteristics" below.|
|Transparency||Opaque to translucent.|
|Optics||Optics: o = 1.496; e = 1.502. Uniaxial (+) or (—). May be anomalously biaxial with 2V from 0° to 10°.|
|Etymology||After the type locality, Tugtup agtakôrfia Ilimaussaq. Tugtup means “reindeer” in the Greenlandic Inuit language.|
|Occurrence||Hydrothermal veins in nepheline syenite pegmatite.|
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. 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.
Tugtupite’s abundance has declined in the years since its discovery. Thus, it’s become somewhat hard to obtain, especially in cuttable pieces.
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).
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.
- 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.
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.
Other sources of this rare mineral include:
- 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. Although 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.
This gemstone’s hardness can range from 4 to 6.5. On the softer end, a knife could scratch one. On the harder end, a tugtupite could exceed the hardness of more commonly encountered jewelry stones, such as feldspars. However, their distinct cleavage makes these stones better suited for protected ring settings and pendants or earrings. 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.
Store these gems separately from other harder stones such as quartz or topaz to avoid contact scratches. For cleaning, use a soft brush, mild detergent, and warm water. Avoid mechanical cleaning. Consult our Gemstone Jewelry Cleaning Guide for more recommendations.