There is a characteristic that is much like diamond dusting that I call a "metallic" edge. When it is seen it is typically on gold or silver edges, not ones that are just white or yellow. If any of you are familiar with automotive paint, the effect of the metallic edge is much like what was once referred to as a "metal-flake" paint job. The painting process used a layer of silver or gold paint that included tiny flakes of aluminum and then a top layer of paint that was clear with only a color in it. This resulted in seeing the color of the top coating, but seeing the sparkling of the aluminum flakes through the color, and as the light hit the paint job from different angles, the flakes sparkled.
I have asked a few people if they could explain what the flakes in the daylily edging consist of, but I have not gotten an answer yet. Here is a close up picture of a toothy seedling I have grown for a couple of years with the metallic appearance. You can see something in the gold edging, but I cannot get enough resolution from the picture for you to see the metallic-looking flakes clearly.
Larry