Chemical formula: Na8Al6Si6O24Cl2. Hardness = 6.0, Density = 2.29
Greenland fluorescent sodalite is found throughout the various complexes in large quantities. Much of it is the typical gray or yellow variety, and almost all of it fluoresces a bright orange. Walking along the mountain trials at night is much like night prospecting in the Franklin NJ dumps - but instead of the ever present orange glow from calcite, it's an orange glow from sodalite.
Certain areas are known for high-quality, vibrantly colored sodalite. The Gronnedal-Ika Complex (near the Arsuk Fjord) contains vein fillings and dissemination of blue sodalite. The color is intense and well suited for polishing. Tumbled sodalite is also a great way to polish these stones. Within the Ilimaussaq Complex there is an area which yields a highly tenebrescent green sodalite (variety hackmanite), mixed with brightly fluorescent green uranyl activated fluorescing mineral. One type is so deeply tenebrescent we have nicknamed it "Chameleon Sodalite".
Sodalite ranges in (daylight) color from blue, white, pink, gray, green, yellow and most (to date) fluoresce a brilliant orange under long wave UV. SW fluorescence varies depending on the type and locale, as does tenebrescence. The tenebrescent qualities of Greenland sodalite are perhaps one of the more technically interesting aspects of this mineral.
Found in the Kangerlussaq area, green sodalite is a vibrant green under day light, much of it gem quality. When exposed to SW UV it is very tenebrescent. Most pieces consist of sodalite interspersed in a lujavrite matrix, along with aegirine and occasionally steenstrupine. Usually a green uranyl activated FL coats many of the pieces.
Found around the same area as the blue sodalite is a variety of sodalite which appears red in daylight. The red color is due to the extreme tenebrescence of this material. When exposed to sunlight it turns a reddish color.
The southern shore of the Tunuliarfik Fjord yields an unusual blue sodalite which is quite tenbrescent and very fluorescent (seldom seen in blue sodalite). These make some great tumbled sodalite pieces.
The Taseq Slopes offer many varieties of sodalite but none match the beauty of pieces which are a gemmy yellow color in daylight. In addition to their brilliance under UV, these pieces exhibit a deep purple tenebrescense - one of the deepest color changes of all the minerals from the complex.
Some sodalite has the outward appearance of albite, but can glow a multitude of colors (this type of sodalite is often associated with many other minerals.
Each locality produces many varieties of sodalite, some very fluorescent, some tenebrescent - often mixed with other minerals to make unusual display specimens. Those which do not assume a specific form or characteristic are listed here.