In the right lighting (bright light), you can hold an aixiz lens up to the diode and see the same thing. Very cool! Its also cool to hold the lens against an LCD screen and see all the pixels.
That are metal shavings at high magification.
I was harvesting the diode from a 20x DVD-burner and use a Dremel to open the metal heatsink. Just after the diode popped out I took the picture. It wasn't cleaned yet. It was cleaned before I press it in the module.