As adjectives the difference between impervious and implacable
is that impervious
is unaffected or unable to be affected by while implacable
is not able to be placated or appeased.
Unaffected or unable to be affected by.
, title=(The Celebrity
, passage=Although the Celebrity was almost impervious
to sarcasm, he was now beginning to exhibit visible signs of uneasiness, the consciousness dawning upon him that his eccentricity was not receiving the ovation it merited.}}
Preventive of any penetration; impenetrable, impermeable, particularly of water.
Immune to damage or effect.
Not able to be placated or appeased.