A "straight brilliance" comes from polishing, layer by layer.
The smoothness of a mirror finish isn't achieved in one pass. From coarse abrasives to ever finer ones — polished through many stages — it finally reaches a mirror-like surface. The slightest unevenness would distort the light. That is exactly why this finish brings an artisan's careful handwork to life.
On an engagement ring, a mirror finish enhances the brilliance of the diamond. The straight surface catches the stone's light, and the whole fingertip glitters brightly — colouring the special moment of a proposal with glamour.
Small scratches picked up over time can be restored to like-new brilliance by re-polishing. Long and lovely — that you can keep its dignified shine forever is part of the mirror finish's charm.