Luster in gems and gold; opening of Of Reflections
Transparent colour of rubies; highlights move with the light or the eye
This leaf closes the section on luster and opens the section on reflections. It observes that the luster within transparent gems such as the ruby and balas ruby shows the finest degree of their colour because the eye sees the highlight through the whole natural colour of the stone, and that reflected lights in the folds of drawn gold surpass the metal's own colour by reverberating from surface to surface without end. It further notes that a lustrous transparent body casts no shadow upon itself, as the shadows of river bridges appear only on turbid water, and that a highlight shifts across an object as the light or the eye moves. The section DE' REFLESSI (Of Reflections) then begins with chapter 780. The page is continuous text with no drawing.
On this page
The colour of luster seen through transparent gems
The luster within transparent stones such as the ruby, balas ruby and glass shows their colour in its first degree of beauty, because between the eye and that highlight the whole natural colour of the transparent body is interposed. The viewer thus sees the highlight steeped in the full body of the gem's hue.
Reflected light in the folds of drawn gold, and no self-shadow
Reflected lights of dense lustrous bodies surpass their natural colour, as in the opening folds of spun gold, where each surface reverberates into the one opposite and back again endlessly. A lustrous transparent body shows no shadow upon itself, just as the shadows of river bridges appear only on turbid water and not on clear water.
A highlight moves with the light or with the eye
The luster is found on objects in as many sites as there are places from which it is seen. With eye and object still, the luster moves as the light moves; with light and object still, it moves with the eye, arising on polished surfaces the denser and smoother they are.