Gypsum from Alberta, Canada
Under daylight. The crystal is about two inches long, one inch wide
Under Short-Wave. The crystal shows similar fluorescence zoning under mid-wave and long-wave.
A selenite crystal from Jet, Oklahoma under day light. The crystal shows hourglass inclusion of silt in a pattern similar to the crystal from Alberta, Canada. The translucent part of the crystal fluoresces creamy yellow
The inclusion of various dye molecules into crystal lattices has been extensively studied by Dr. M. McBride (Dept. Chemistry, Yale University) and Dr. B. Kahr (Dept. Chemistry, University of Washinton). Some of the crystals produced in Dr. Kahr's laboratory show remarkable resemblance to the hourglass gypsum.
Click Here to View Dr. Kahr's Crystals
Especially,
Laser dye of sulforhodamine B in the {110} sectors of K2SO4.
KH2PO4 crystals containing dyes in the {101} growth sectors