Nice little specimen of deeply tenebrescent hackmanite with [richterite?] from the Koksha Valley, Kuran Wa Munjan District, Badakhshan, Afghanistan, that was kindly donated to me by a member of the fluorescent minerals facebook group. This is the very first Afghan fluorescent mineral specimen added in my collection; I was already aware that many nice fluorescent minerals came out of Afghanistan, but seeing one in person got me hooked to Afgani minerals! It didn't take long until I started acquiring other Afghani minerals after I received this one!
What's interesting with this specimen is that it's the very first one I noticed reacted very differently under conventionnal 254 nm shortwave UV tubes, and 255 nm shortwave UV LEDs. Under 254 nm, the slight emission of midwave and longwave generated make the specimen fluoresce pink and white, while the much narrower, purer UVC spectra emmited by 255 nm shortwave UV LEDs produces a blue and pinkish response. With UVC LEDs, we will discover the true shortwave response of some minerals that would otherwise react differently under the broader spectrum of conventionnal mercury vapor UVC tubes. Shown below, respectively: Longwave UV, LW UV phosphorescence, LW UV tenebrescence, midwave UV (310 nm LED), shortwave UV (conventional 254 nm mercury vapor bulb), SW (255 nm LED), SW phosphorescence, SW tenebrescence, natural color. Size: 6,5 cm X 3,8 cm X 3,2 cm
Longwave UV fluorescence
Longwave UV phosphorescence
Longwave UV tenebrescence
Midwave UV (310 nm LED) fluorescence
Shortwave UV (conventional 254 nm mercury vapor bulb)
Shortwave UV (255 nm UVC LED)
Shortwave UV phosphorescence
Shortwave UV tenebrescence
Natural color.