For using Counterspell, a spell needs to contain some kind of component, otherwise it cant be countered.
Subtle Spell is meant to protect a spell w/o material components from counterspell, since you can't see the casting. https://t.co/Q7IhCeMWhH
— Jeremy Crawford (@JeremyECrawford) September 10, 2015
When casting spells from magical items the spell is cast at the lowest possible spell level, doesn’t expend any of the user’s spell slots, and requires no components, unless the item’s description says otherwise. DMG p141.
spells you cast from items can be countered
So, does it mean that the magic items are considered as the material components of the spell?