If this is about sparkles in only sunlit areas, and not in shadows, luminosity won't work, as I wrote in the sparkle topic. I might have something, but must test again today. Simply said: get some tiny fake stones, no color (=black) attach a powerfractal for extra tiny displacement (more areas that might sparkle), no color (or black, I can't recall what I did). Then a reflective shader with high settings, all blended by a tiny fractal, color shoved to the left. I'll make a tgd/tgc if I got a decent snowscape.
If this is about snow/vegetationtypes in shadowed areas, and not in sunlit areas, it's an interesting approach, FrankB.
---Dune