Tugtupite – origin, colour, and characteristics
Tugtupite is one of the most sought-after Greenlandic minerals. The name comes from the Greenlandic word for reindeer, 'tuttu', and the stone is therefore also called reindeer bloodstone. It was described in the late 1950s from the Ilímaussaq complex in South Greenland and is known for a rare optical phenomenon: its colour intensifies when exposed to daylight or UV light.
What you need to know about Tugtupite
Geology, not healing: We describe mineralogy, origin and appearance – not effects or healing claims.
Fact-based reference knowledge: Origin, mineralogy, colour and hardness compiled in one place – written for jewellery makers and collectors.
Our own stones in stock: However, we have thousands of genuine stones and crystals in our shop at Nybrovej 83 in Gentofte.
What is tenebrescence?
Tenebrescence is a reversible colour change: the mineral darkens when exposed to daylight or UV, and slowly returns to a lighter colour in darkness. This effect is due to structural defects in the crystal lattice that temporarily trap electrons, and it can be repeated many times.
It is precisely this property that makes tugtupite so renowned among collectors. A stone that appears pale pink in a display case can become vividly red after exposure to sunlight.
Where does the stone come from?
Tugtupite was discovered and described in the Ilímaussaq complex in South Greenland, an alkaline intrusive complex known for an unusually rich mineral content. The area has given its name to several minerals that have not been described in many other places in the world.
The mineral has since been found in similar alkaline environments outside Greenland, but Greenlandic material remains the most well-known in the trade.
Characteristics of genuine material
- The colour is rarely completely uniform – typically, pink areas are seen within a lighter or greyish matrix.
- The effect can be tested: place the stone in sunlight for a few minutes and compare it with a photo taken beforehand.
- The surface is softer than quartz, so polished facets may show fine scratches with use.
- The seller should be able to state the locality; rare stones without provenance are a red flag.
How to use this page
This page is written as reference knowledge for jewellers and collectors: detailing the stone's geology, origin, appearance, and what to be aware of regarding processing and authenticity.
If you wish to work further with natural stones, you will find overviews of genuine stones, crystals, and semi-precious stones – strands, loose beads, and rough chunks – under 'Stones & Crystals'.
FAQ
Why does Tugtupite change colour?
Due to tenebrescence: light temporarily changes the electron distribution in the crystal lattice, deepening the colour. In darkness, the colour gradually reverts. The effect is reversible.
How hard is Tugtupite?
Typically around 4-6 on the Mohs scale, meaning softer than quartz. It is best suited for pendants, brooches, and earrings rather than rings, which are exposed to wear.
Is Tugtupite only found in Greenland?
No, the mineral has also been found in similar alkaline rocks in Russia and Canada, among others, but the Greenlandic material from Ilímaussaq is the most well-known.