I am making a shell themed cake for a 50th wedding anniversary, and want to add some "sea glass" to it for a color element. I tried this once before, (cooking sugar to hard crack, coloring, and pouring over parchment to set. Broke it into pieces and tossed with conf. sugar for effect), the trouble is that the candy pieces "absorbed" the conf. sugar and continued to be a bit soft and sticky. Any advice/instruction on what I may have done wrong and what I might to do improve my outcome?? Thank you in advance for your assistance :)

I think you are hoping for the 'frosted' affect that sea/beach glass has - which would be very pretty.  I wonder if tinted isomalt dusted with extra fine sugar would work.  Or isomalt handled with white cotton gloves and then dusted with a complimenting dust - might give the tumbled effect.  Just throwing out ideas - as I have NOT tried any of the techniques I'm suggesting to get a beach glass look.  I'm sure others will weigh in.   

Things to consider, fundant! Any ideas are helpful! :)