|
Hackmanite -
Koksha Valley, Badakshan Province,
Afghanistan
|
|
|
|
Normal light
|
Longwave
ultraviolet
|
This specimen is from
Afghanistan. The purple you see under normal light is hackmanite and
it is tenebrescent. It fluoresce pink/orange under longwave
ultraviolet, but less intense under shortwave UV. It phosphoresces
white after exposure to shortwave UV.
Under normal night, the purple
color fades to a light purple color. Before taking the picture under
normal light. It was exposed to shortwave ultraviolet for a few
minutes to darken the purple color.
This phenomenon is called
tenebrescence meaning photochromic.
It's size is 3" long by 1 3/4" wide by 1 1/4" thick
Other minerals exhibit this
behavior is Tugtupite
and sodalite.
Back to
Fluorescent Minerals photo list