Abstract
This project on the evaluation of Greenlandic rubies is part of a collaboration project between the Ministry of Mineral Resources in Nuuk, Greenland, and the Geological Survey of Denmark and Greenland, Copenhagen & Nuuk, Denmark. The investigations are mainly focused on characterisation of the Fiskenæsset complex ruby/sapphire, because a mine is currently being built in the most promising ruby outcrop in that area, Aappaluttoq, by the Canadian company True North Gems (TNG).
The activities in 2014 consist of multivariate statistics analyses of the geochemical results for the ruby/sapphire samples that were collected in 2011-2013 (Chapter 2). We show that Aappaluttoq samples, especially the samples with an intensive red colour, have a rather unique geochemical signature, or ‘fingerprint’, but still have a close resemblance to some international mafic-ultramafic occurrences.
Mineral inclusions and other internal growth features were studied with an optical stereo microscope. Anthophyllite and phlogopite are common mineral inclusions in samples from the Fiskenæsset complex, while milky zones, zonal clouds form typical internal features. A range of features, including trace element geochemistry, oxygen isotope values and internal features, needs to be investigated to be able –in some cases- to separate samples from Fiskenæsset from other international occurrences.
The project included some travelling activity in 2014, both for educational (Dubai, Chapter 4) and for dissemination purposes (GIT conference in Thailand, where an abstract was presented on the comparison of geochemical methods for fingerprinting of Greenlandic gem-corundum (ruby/sapphire)). The abstract and poster for the GIT conference are added as Appendix.
The samples from the Fiskenæsset area contain both ruby (reddish colours) and sapphire in various shades of pink. Only transparent medium light to dark tones of red to purple red coloured corundum can be defined as ruby. Stones that have light to medium light tone are called pink sapphire. Not all the stones investigated are of gem-quality, and therefore the word for corundum will be used for both ruby and pink sapphire in the following text, unless the actual colours of the ruby/sapphire are described. Even here will ruby or sapphire describe a specific colour of corundum of gem or none-gem quality.
The activities in 2014 consist of multivariate statistics analyses of the geochemical results for the ruby/sapphire samples that were collected in 2011-2013 (Chapter 2). We show that Aappaluttoq samples, especially the samples with an intensive red colour, have a rather unique geochemical signature, or ‘fingerprint’, but still have a close resemblance to some international mafic-ultramafic occurrences.
Mineral inclusions and other internal growth features were studied with an optical stereo microscope. Anthophyllite and phlogopite are common mineral inclusions in samples from the Fiskenæsset complex, while milky zones, zonal clouds form typical internal features. A range of features, including trace element geochemistry, oxygen isotope values and internal features, needs to be investigated to be able –in some cases- to separate samples from Fiskenæsset from other international occurrences.
The project included some travelling activity in 2014, both for educational (Dubai, Chapter 4) and for dissemination purposes (GIT conference in Thailand, where an abstract was presented on the comparison of geochemical methods for fingerprinting of Greenlandic gem-corundum (ruby/sapphire)). The abstract and poster for the GIT conference are added as Appendix.
The samples from the Fiskenæsset area contain both ruby (reddish colours) and sapphire in various shades of pink. Only transparent medium light to dark tones of red to purple red coloured corundum can be defined as ruby. Stones that have light to medium light tone are called pink sapphire. Not all the stones investigated are of gem-quality, and therefore the word for corundum will be used for both ruby and pink sapphire in the following text, unless the actual colours of the ruby/sapphire are described. Even here will ruby or sapphire describe a specific colour of corundum of gem or none-gem quality.
| Original language | English |
|---|---|
| Place of Publication | Copenhagen |
| Publisher | GEUS |
| Number of pages | 29 |
| Volume | 2016 |
| DOIs | |
| Publication status | Published - 27 May 2016 |
Publication series
| Series | Danmarks og Grønlands Geologiske Undersøgelse Rapport |
|---|---|
| Number | 20 |
| Volume | 2016 |
Keywords
- Greenland
Programme Area
- Programme Area 4: Mineral Resources