The Fluorescent Minerals of Greenland - An Overview

Overview of Greenland and the Fluorescent Minerals from this Locality

We will divide this blog into a 5 series post with a focus on the following areas:

1. Overview of Greenland and the Fluorescent Minerals from this Locality
2. Taseq Slope Minerals
3. Kvanefjeld Minerals
4. Tunuliarfik Minerals
5. Kangerlussaq Minerals

Franklin, New Jersey USA

Most fluorescent collectors started out collecting Franklin fluorescent minerals. They are among the brightest and most sought after fluorescent minerals known to the hobby. Miners discovered the amazing fluorescent properties of many minerals from the Franklin, New Jersey mines 100 years ago. Throughout this last century, scientists such as Charles Palache, Clifford Frondel, Pete Dunn and others have studied the mineralogy of the New Jersey mines and slowly identified each mineral. Mineral collectors have explored the fluorescent properties of these minerals for years. Even today new minerals are being identified!

Ilimaussaq Complex, Greenland

The Ilimaussaq complex in Southern Greenland has been a famous center for geological exploration for hundreds of years. As early as 1806, mineralogists were exploring the unique geology of the complex; since then over two hundred minerals have been identified within the intrusion. Many are only known from a few areas in the world, and at least ten are unique to Ilimaussaq. The complex is also the type locale for dozens of species. 

But Greenland’s fluorescent minerals have largely been ignored! 

Until 2000, only tugtupite was recognized as a significant (and very rare) fluorescent mineral from Greenland; some collectors were aware of fluorescent sodalite but little was available on the open market. Over previous years, remote areas of the complex have yielded scores of fluorescent varieties of tugtupite, sodalite, sorensenite, polylithionite, and ussingite. Many unidentified minerals have been found -- but make wonderfully glowing rocks!

Fluorescent collecting in the Ilimaussaq complex can probably be equated to the 1950’s around Franklin. Imagine the first collector who discovered the fluorescent properties of margarosanite! The excitement of discovering and collecting these new minerals, from an entirely new locale, adds a valuable new dimension to the fluorescent mineral hobby. A few knowledgeable people have picked up on this new material and are slowly and methodically analyzing them. Many of the Greenland minerals found today will ultimately be identified, some will be common and perhaps others will be excessively rare -- but all are welcome additions to the hobby.

Today, there are dozens of separate fluorescent minerals identified from the complex, and scores waiting to be identified. The brightness of these pieces, along with many beautiful multi-color combinations, rivals those from the Franklin Sterling Hill area. Many pieces exhibit dramatic phosphorescence or a remarkable tenebrescence (color change) found in few other minerals. No literature exists describing the fluorescence of the various minerals within the complex; few people have even brought a UV light to the area! Yet these minerals simply lie there – waiting for the venturous collector to shine a light on them and find the hobby’s next rarity! Fluorescent collecting in Greenland must be akin to collecting in Franklin in the old days; exciting, productive, and simply fascinating.

Greenland

Greenland, an island covered in ice (albeit, the world’s largest), has a rugged coastline with strips of green in the summer months (Erik the Red named it Greenland after he was booted out of Iceland – the ultimate deception people say. He did it just to make others want to move with him!). Southern Greenland is “warmed” by the Gulf Stream and in the short summer months (June to September) averages in the 50’s to 60’s. But even during these “warm spells” one is amazed at the majestic icebergs floating in all the harbors and fjords, the glaciers, and the lingering snow covering that elusive piece of tugtupite.

Greenland was very much a part of Denmark until 1979 when a “Home Rule” government was established, insuring that the culture and Greenland way of life would not be lost. Denmark still plays a major role in Greenland’s government, but the Greenlandic people control their destiny. They are a proud, self-sufficient people. Living off the land, they are great hunters and fisherman, and very proud of their natural resources. Greenland is one of the few undeveloped natural wonders left on earth one can visit and still experience nature’s beauty and solitude at her finest – without a single worry about terrorism, violence, or crime.

There are no roads connecting the cities (in fact, there are few cities). The larger settlements have roads in town, mostly so people can drive down to their boats – the main mode of travel. Flying into Narsarsuaq (a bustling airport of 200 people) one can travel by ferry or private boat to Narsaq – homebase for those exploring the Ilimaussaq Complex. Narsaq is a small village located about 16km outside the Ilimaussaq Complex. The people are used to geologists traveling there from all over the world. Travel to/from the various areas within the Ilimaussaq complex is by boor 4-wheel drive truck. An old road leads to the famous Kvanefjeld area (Tugtupite mines) and the Taseq slopes. Other parts of the complex are accessible only by boat.

The Ilimaussaq Complex 

The Ilimaussaq Complex in Southwestern Greenland is an 8x17km intrusion spanning two fjords - Kangerluarsuk fjord and Tunuliarfik fjord. Located near the city of Narsaq, access to certain parts of the complex (Kvanefjeld and Taseq) can be made by foot, while other areas (Kangerluarsuk and Tunuliarfik) requires travel by boat. It is without a doubt the most mineral-rich area in Greenland. Due to the rapid weathering of the friable (brittle and easily crumbled) syenites most of the mountains have no vegetation (no soil). The gray “rockscape” contrasts sharply with the deep blue fjords and gleaming white icebergs.

The 1.2 million year old intrusion consists of three different rock suites. Nepheline-bearing augite syenite first formed a shell along the sides and the roof, next a quartz bearing alkali granite and alkali syenite formed two thin sheets near the top, and finally the biggest part and center of the intrusion was formed by a layered series of under-saturated syenites. These three main rock suites represent three pulses of different kinds of magmas. The rocks close to the roof are the oldest. The most common rocks in these areas are a sodalite-nepheline syenite called naujaite, an arfvedsonite-aegirine bearing nepheline syenite called lujavrite, and a eudialyte-bearing nepheline syenite called kakortokite.

Old geological map of the Ilimaussaq Complex – based of a map by Ferguson (1964) and since corrected and improved.

Updated geological map of the Ilimaussaq Complex, Courtesy of Alex Strekeisen. Modified from Hunt (2017).

Ilimaussaq hosts the widest variety of minerals in Greenland - more than 200 so far, half of them silicates. The silica content of these minerals is much higher than elsewhere in the world. Numerous pegmatites and hydrothermal veins, streaks and patches are found all over the intrusion, but are most common in the areas of Kangerluarsuk and Kvanefjeld.

There are several key localities within the complex. Some of these areas are small intrusions perhaps only meters wide. Many minerals in these areas are found nowhere else in the world.

Each area within the Ilimaussaq Complex yields distinctly different varieties of the more commonly found minerals. Therefore, a discussion of each variety found in each of the four major areas (Kvanefjeld, Taseq Slopes, Tunuliarfik, and Kangerlussaq) is appropriate.

Mysteries

Fluorescent minerals from the Ilimaussaq Complex are slowly being identified as they are found. This process is time consuming and difficult; many specimens contain unknown minerals, with wonderful fluorescence. The purist would first identify minerals before presenting them to the collecting public – but that takes half the fun out of the hobby.

Summary

The fluorescent minerals of Greenland bring a new and exciting challenge to the hobby. Dozens of new very collectable varieties are being found. As can be seen from this series, many are combinations of just a few rare and exotic minerals – mixed together to create simply awesome specimens. In many cases, it has proven extremely difficult to identify some finds. And only the surface has been touched – literally! Collecting in Greenland to date has been focused on surface rocks. Over the coming years veins will be explored and fresh material brought to light that has never seen sunlight. Knowledgeable collectors are making trips to the complex and making new discoveries every year. Who knows what is waiting to be discovered?