>Can anyone recommend a good source for microscopic images of crystals (gems,
>minerals, snow, ice, sugar, anything)?

Many of the CD ROMs found in the back of Photoshop books include stock
photography. While preparing to teach this smemester, I reviewed a number
of these and recall that the subject was not uncommon. I believe that one
company in particular had a number of crystal images included. I'll try and
see if I can track down which one it was.

Frank