For a while I've been infatuated with tenebrescence or photochromism in minerals. That is to say the ability for that mineral to change color when put under UV light and back. In this case the marialite goes from a clear white in daylight to a dark blue after you put it under LW. This process can then be reversed by exposing it to white light. I've been infatuated with this phenomenon ever since I learned about it in the minerals of Greenland, specifically the hackmanite and tugtupite. However, I was never able to win any eBay listings for a price that I wanted. Not being able to crave this desire I decided to look up other listings for tenebrescent minerals. That's when I came across the marialite (though the dealers there mostly refer to it as scapolite) from Pitwak. It greatly appealed to me as it had the same deep color change that Greenland had while forming beautiful crystals. That was 3 years ago and I've since been searching for great crystals like this. I haven't even had the remote thought of purchasing any Greenland fluorescents for my collection.
Of note on this specimen is that it shows little tenebrescent response under 253.7nm SW. The response is strongest under 365nm LW. This is typically the other way around where the strongest response is achieved under SW. This specimen has also been irradiated. Funnily enough the cousin of the miner that collected this specimen got in contact with me through Facebook. Often times Pakistani mineral dealers will try to sell by sending friend request to people in mineral groups en masse. I usually just show them this specimen and say that I'm looking for at least this or better. That's when it was recognized by the miner's cousin. I'm inclined to believe him as he provided up to date photographs of Pitwak mine that aren't available elsewhere on the web.
Locale: Pitwak Mine, Kokscha Valley, Badakhshan Province, Afghanistan
Weight: 6.1oz | 174g
Dimensions: 3.3 x 1.9 x 1.4 in| 83 x 48 x 37 mm