Avicularia purpurea molt - iridescence on the exoskeleton

I had to look up iridescence, to figure out how to spell it, and I hadn't really thought about the definition, but here it is, via wikipedia:

Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change colour as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, butterfly wings and sea shells, as well as certain minerals.

Apparently another example is the footpads of Avicularia species tarantulas.

I am really grooving on taking shots of post-molt exoskeletons. After all, you have all the time in the world to set up the shot. And I got some nice shots of the iridescence that I have been noticing in certain lights on their foot pads. And I also got a nice shot of those needle-sharp fangs. This molt had being hanging around for quite awhile at the bottom of Arabella's silk home. She seemed to be increasingly bothered by it, avoiding that end of the home, occasionally going down and pushing on it a bit. So today I decided that perhaps she would prefer it gone. Usually tarantulas decide themselves when to kick the molt out.  Most of them seem to keep them for at least a few days, not sure why. Maybe just recovering enough to have the energy to do the job.