Ruby-and sapphirine-bearing mineral occurrences at Fiskenaesset area, and Nuuk and Maniitsoq regions, West Greenland

The Fiskenaesset anorthosite complex in the Archean block of West Greenland hosts many ruby/sapphirine occurrences. These occurrences furthermore contain other rare minerals such as kornerupine, gedrite, enstatite, cordierite, red spinel, pargasite and phlogopite. The report describes the geological setting of the ruby/sapphirine occurrences, mostly found in ultramafic layers and lenses along the contacts between anorthosite and amphibolite.

The report introduces a ruby/sapphirine portal at the web site of the Geological Survey of Denmark and Greenland (GEUS) with a short description of 28 localities comprising 87 occurrences. The portal gives access to a detailed inventory comprising literature references, geological maps, diaries and relinquished non-confidential company reports. The report presents an overview of the most common mineral parageneses, with special emphasis on the occurrences of ruby corundum and sapphirine.

A history of exploration is presented from the first collection of sapphirine in 1809, over the discovery of rubies in 1966, to the beginning commercial prospecting in the 1970’es and 1980’es, up to the recent activities by the Canadian company True North Gems Ltd. starting in 2004. The description and data base portal does not comprise the ruby localities found by True North Gems Ltd. due to confidentiality reasons.

One of the occurrences – Aappaluttoq – is by True North Gems Ltd. expected to contain enough rubies and pink sapphires of gem quality to form the basis for an industrial production. An open pit is prepared for exploitation planned to start in 2015. In addition to the description of the Fiskenaesset localities the report in the Appendix contains a summary of six ruby/sapphirine localities from the Nuuk and Maniitsoq regions.