Resist Elemental Damage Occupies 1 enchantment slot on a armor.
Two elements can be combined as long as they are components of an advanced element in a single slot, however they become slightly less effective.
Elemental:
Focused Resistance
+2/+4/+6 to Chosen SINGLE Element.
Price +1/2/3 bonus.
Enchantment Orb: Matching Element Orb x1/x3/x5
Advanced Resistance
+1/+3/+5 to Chosen Two Elements that make up an advanced one..
Price +2/4/6 bonus.
Enchantment Orb: Matching Element Orb x1/x3/x5 of both types.
Light
+1/+3/+5 to Chosen Element.
+3/+6/+9 to Perception
Price +2/4/6 bonus.
Enchantment Orb: Light Orb x1/x3/x5
Shadow
+1/+3/+5 to Chosen Element.
+3/+6/+9 to Stealth
Price +2/4/6 bonus.
Enchantment Orb: Shadow Orb x1/x3/x5