Brilliancy; splendor; brightness; glitter. [1913 Webster
" There is a tendency to limit the use of luster, in this sense, to the brightness of things which do not shine with their own light, or at least do not blaze or glow with heat. One speaks of the luster of a diamond, or of silk, or even of the stars, but not often now of the luster of the sun, a coal of fire, or the like."
"The right mark and very true luster of the diamond."
"The scorching sun was mounted high,
In all its luster, to the noonday sky."