Hackmanite, the fluorescent Sodalite
I love cutting up fluorescent stones, it always feels like I am looking for treasure!
Recently I have decided to cut up some Hackmanite from Greenland that I have hoarded for a few years. It is a forest green on the outside, but when I first slabbed it up, there was like this wine coloured middle part. I was so awestruck I took a picture of it, and I am super lucky that I had, because when I went outside in the sun to get better lighting, this colour disappeared!
Never seen the light of day vs First sight of sun
I had made a custom pair of 7/16" plugs for an order, and was once again blown away by the beauty of this stone found in its fluorescence:
7/16" Greenland Hackmanite plugs
According to mindat.org, Hackmanite is a variant of Sodalite which contains traces of Sulfur. The fluorescent community have reserved the name Hackmanite for Sodalites that display tenebrescence. Tenebrescence is when the colour changes due to UV radiation: that's right! This stone can change colour in the sun!
That not only makes sense for the larger Hackmanite from Greenland, shown above, but I have also worked with the ever rare Hackmanite from Afghanistan:
Hackmanite from Afghanistan - both Fluorescent and Tenebrescent
Hackmanite can be found mixed in with various minerals as well. Those are my favourite because they give extra dimension:
The fluorescent part is Greenland Hackmanite, shown alongside Ussingite and unknown black mineral.
Needless to say, I am don't see myself being done with the exploration of this stone any time soon, as there are more areas of the world that produces this stone that I have yet to carve ;)