Douglas Harper's Etymology Dictionary
immaculacy
1799; see immaculate + -cy.
Wiktionary
immaculacy
n. immaculateness.
Usage examples of "immaculacy".
He remembered the immaculacy of the inland sky, riot a cloud, not a grain of dust between the earth and the planets.
Every one of those panels was done aboard a ship, well out at sea, so that not a speck of dust could mar the immaculacy of the lacquer.