New snow and ice blocks:

From left to right:
Slush (wet snow), soft snow, snow, packing snow, white ice, pure ice.
Note that pure ice is semitransparent, while white ice is opaque. Pure ice is considered to be harder (and probably rarer) than white ice. This could make for interesting ice caves. :)
It is planned that the slush is unstable in real gameplay. I plan to destroy slush as soon as something collides with it. I also plan to add more special behaviours to the soft snow. As I said, I’ll postpone most gameplay-related stuff to version 5.0.
Maybe I’ll add up to 2 more snow types; I am not sure yet.
The snow and ice also comes with some different footstep sounds.
And the lumps now support the wetness levels, too. Sadly, there are still no sand “lump” (or something) like that. I have to think of something good.
Inventory images of lumps:

I already explained lumps in my previous post.
The 3 funny-looking rectangles are stones, you get them when you mine gravel. Stones are special; they are no wet counterparts of them, you always get dry stones.
The number of dots for each lump image indicates the wetness level. Annoyingly, the dots appear also in the image of the dropped item. It seems I can’t do much about that. :/
Grab v1.2 here: http://repo.or.cz/w/minetest_pedology.g ... b0949d.zip (Rename the folder in it to “pedology”, put in mods folder.)