Question of powders that add elemental buffs

if i have a weapon that has cold damage (naturally) or because i inserted a gem, will this effect stack with the cold powder? will the freeze build up increase? will the damage increase? thank you for your feedback

Elemental oils give weapon elemental infusion effect. They override any infusions you might have from enchantments or gem. However, they do not give any damage or buildup increases, even if you have 2 of same infusion at the same time.