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Hackmanite Specimens
Hackmanite is a very special and rare variety of sodalite. This amazing mineral possesses the ability to
change color when exposed to ultraviolet radiation (both UV from a UV lamp and UV from the direct sun). This phenomenon, known
as tenebrescence, is a reversible photochroism. In other words, the color change is not permanent and can be repeated indefinitely.
However if the stones is heated, its ability to change color is destroyed. Typical color changes for rare Burmese hackmanites
specimens are from colorless, light pink, blue or purple to intense blue or deep purple. According to the quality - i.e. purity
- of the hackmanite specimen, the color change is naked eye visible in few seconds, whereas the return of the initial color
may take between hours and one week when stored in a complete dark area. The most sought after specimens are those with a
color change from colorless or very light color to intense deep purple. Hackmanite will also fluoresce a patchy orange
under UV light, and if you let the UV light charge the stone up for a couple of minutes, it will phosphoresce a white or slight
blue color in the dark.
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Incredible crystal of hackmanite from Sar-e-Sang, Kokcha Valley, Badakhshan, Afghanistan. There is also a pretty
cool little, oxidized, irridescent pyrite crystal on this piece, just barely visible on the upper left in the left photo.
Approx. size: 31x13x27 Weight: 9.2 grams
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The color of this piece has actually darkened since the photo was taken and it's now a rich purple color. Very
nice specimen from Sar-e-Sang, Kokcha Valley, Badakhshan, Afghanistan. mounted in a 1½" perky box. Approx. size:
27x24x18 Weight: 9.7 grams
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In addition to the hackmanite on this specimen from Sar-e-Sang, Kokcha Valley, Badakhshan, Afghanistan there is also
a piece of achroite crystal lying next to one of the hackmanite pieces. Approx. size: 34x20x35 Weight: 23.2 grams
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