What you think is the reason if their non inclusion in skyrim ? Is there something like the new materials introduced that replaces them? Would them be alloys now or still collectable raw materials? Should be threated differently because of a better realism in skyrim and a "ice" material would look out of place ?

What actually are the origins of those two types of materials and finally I read somewhere that the etimology of stalrhim comes fromancient norvegian meaning ice steel possible?

Brush up on your lore.

Stalhrim is only found on Solstheim, as caskets. And it requires a special pick to harvest. And it's extremely taboo to do. It would be like... harvesting the gravestones in Arlingonton National Cemetary for your armor and weapons.

I'd say they were just left out for dev reasons.