All 11 Uses of

luminous
in
The Fountainhead

It was a large, bare room, made luminous by the clean glow of whitewash.†
Chpt 1.1 *

The sky was growing dark and luminous as blue-green glass; the buildings looked like clouds condensed on the glass, gray-blue clouds frozen for an instant in straight angles and vertical shafts, with the sunset caught in the spires.... As the summer months passed, as his list was exhausted and he returned again to the places that had refused him once, Roark found that a few things were known about him and he heard the same words—spoken bluntly or timidly or angrily or apologetically—"You were kicked out of Stanton.†
Chpt 1.8

And in that heightened state of luminous vision, his head nodding over a glass but his mind steady, he told himself that he had nothing to regret; he had done what anyone would have done; Catherine had said it, he was selfish; everybody was selfish; it was not a pretty thing, to be selfish, but he was not alone in it; he had merely been luckier than most; he had been, because he was better than most; he felt fine; he hoped the useless questions would never come back to him again; every man for himself, he muttered, falling asleep on the table.†
Chpt 1.15

The leaves hung without motion against a sky of polished lemon yellow; its luminous pallor emphasized that its light was failing.†
Chpt 2.1

The place lay deserted, cut off from the world, dissolved in darkness; but the sky glowed, too luminous for the night below, as if the light had remained past the normal hour, in announcement of the coming spring.†
Chpt 2.11

The corners blurred, gathering darkness; the window remained luminous, evening light rising from the earth.†
Chpt 3.5

Wynand's eyes seemed whiter than usual, as if the blue had ebbed from the iris, two white ovals, luminous on his face.†
Chpt 4.3

Her voice had a luminous simplicity; she was being carried along, unresisting, any personal reaction would be superfluous, even pain or fear.†
Chpt 4.4

She walked down the hill and she found relief in the unnatural stillness of the earth around her, the stillness of full light without sun, of leaves without motion, of a luminous, waiting silence.†
Chpt 4.9

Then he saw the fit of fury he had expected for days and had thought safely sidetracked—the blue irises vanishing in a white smear, the blind, luminous eyeballs in a face that was all cavities, the trembling hands.†
Chpt 4.15

Definitions:

(1) (luminous)
glowing or shining

(also used metaphorically to describe beauty or intelligence)
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much more rarely, luminous can mean beautiful, inspiring, or beautifully clear and understandable.