Hi guys! I’ve been wondering how to achieve this white look of salt.
Hope for your help!!
Not good at materials at all… 
but i guess some subsurface scattereing and/or some transmisson may help ??
i would approach as @Okidoki said. subsurface and transmission with roughness.
i will maybe add a volume and a coat for extra controls
here is a quick attempt (it doesn’t look perfect with quick noise texture and displace modifier on spheres but maybe it will get you started) note the subsurface radius changed to make it blueish instead of reddish
having better maps on left side to draw noise and roughness will makes it better.
good luck
Much better at materails as it seems 
Not really. It’s a matter of luck for me. I m litteraly struggling with my own project material right now and keep failing. 
try to reduce the density of the volume or get rid of it or crank it’s emission a bit?
the scale of the subsurface needs to be adjusted to match your scene scale too
maybe the emitter isn’t hidden in view-port and that’s the white thing you see.
for the dark effect reduce the transmission
To avoid having to crank up the transparent and transmission bounces a lot (which will increase render times too), I’d fake it using a small amount of emission in the volume input.
what do you mean by “it doesn’t change anything”?
They still dark
