From: mroussel@shaw.ca   
      
   On Saturday, April 11, 2020 at 11:33:20 AM UTC-6, omni...@gmail.com wrote:   
      
   > The " transition-metal crystals" that are transparent will be studied,   
   > or you could give an example of a chromium crystal that is transparent.   
      
   In order to get a chromium compound with a d0 configuration, you would have to   
   have chromium in the Cr(V) oxidation state, but there aren't many compounds   
   like that.   
      
   Crystalline scandium(III) compounds should be transparent in the visible range.   
      
   > The conductive indium tin oxide is transparent, like glass, across   
   > many colors.   
      
   Interesting. I guess these transparent conductive oxides are semiconductors   
   with band gaps just big enough not to absorb in the visible.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)