Use "imperviousness" in a sentence

1. It took six weeks of steadily continued mild indifference on Herr Dremmel's part, of placid imperviousness to all approaches of an affectionate nature, of the most obvious keen relish in his work, keener than he had yet shown, to reveal the truth at last to her; and greatly was she astonished

2. Over the last five years Celeste herself had developed a kind of imperviousness and acceptance of violence that allowed her to hit back and sometimes even hit first