Phlogopite, Afghanite, Calcite, with Mysteries - Afghanistan

Contributed by: Mark Cole
Date: Apr 9th, 2026
Locality: Sar-e-Sang, Kuran wa Munjan District, Badakhshan, Afghanistan (See on Mindat)
Size: 2.5 x 2 x 3.5 inches
Weight: 11.6 oz

Description:
This rock reminds me of our early days collecting in the Ilimaussaq Complex of Greenland. At that time, we were finding dozens of fantastically glowing rocks where we had no idea of the IDs. Slowly over the years people smarter than I studied and identified the various minerals and we now have a pretty good handle on most IDs (but not all - not yet).

Afghanistan is at that stage. I\'m confident of most IDs but I simply have no clue. The primary mineral on this specimen is a multi-wave responding phlogopite. Under SW it fluoresces a bright yellow, shifting to a bright butterscotch under MW, and almost red under LW. This is very unusual for phlogopite - perhaps only 10% of the specimens I have handled respond thusly. Note that the matrix contains a lot of phlogopite also.
A little bit of calcite pops out, mostly MW. But the blue fluorescence is a total mystery to me. The opposite side has a couple of brightly fluorescent (orange) spots of afghanite.

This is probably one of the prettiest rocks I\'ve seen under MW.

Originally posted by Mark Cole on Nature's Rainbows in 2017.