Brittle Effect on Enemies

Hi, So I've recently been using a Cold-Attuned Buckler, which says it "inflicts Brittle on enemies when you block their damage"

I've currently got 32% chance to block attack damage and I've stood in front of a mob that has been wailing on me. There's been no visible effect on the enemy, as a visual overlay like chill, or from a change to the text under its name when you mouse over it.

Can anyone confirm if Brittle has a visible effect?

As an aside, does anyone know if the cold-attuned buckler is even working

If Brittle doesn't have a visual effect, I'd strongly suggest adding one