Fluorescence at Low Temperatures
Specimens of Wulfenite that do not fluoresce at room temperature often
fluoresce at lower temperatures. The Wulfenite crystal above from Los Lamentos,
Mexico does not fluoresce at room temperature. It was chilled to well below
freezing when the photograph above was taken. The bluish white coating
on the crystal is a layer of frost that formed on the extremely cold crystal.
When it warms up the orange fluorescence disappears.
Photographic
Images © 2003 James O. Hamblen