We have run out of stock for this item.
*Note: Please make sure to right-click and print (or save) ID card located in the photo gallery for your records*
A piece of nicely tenebrescent hackmanite from Afghanistan.These sodalite hackmanite specimens also display an incredible phosphorescence.
Hackmanite is a pink to greyish-white, lavender to white variety of sodalite. Sulfur replaces some of the chlorine atoms in the sodalite structure. The sulfur content can give sodalite reversible photochromism or tenebrescence. The fluorescent community reserves the name hackmanite for tenebrescent sodalites.
Below is an excerpt from the Journal of the Fluorescent Mineral Society, Volume 39 - “Hackmanite all fluoresce orange in longwave UV light. All of the hackmanites have strong and long-lasting white afterglow after exposure to shortwave UV light. Strong, long-lasting dark purple tenebrescence is associated with these hackmanite specimens. The tenebrescence is very long lasting. It takes several hours under a strong halogen light to reverse the tenebrescence.”
The Garpenberg mine is located in Bergslagen, a very old mining area in the southern part of Sweden.
The mine is very active today and is one of Europe's most progressive underground mining operations. Collecting is not possible, and the few specimens that reach collector's hands are highly prized. The mineralogy is quite similar to that of Franklin NJ.
