The Wyoming and Montana Rockies are hands-down my favorite mountains, but nowhere has rock quite like the Sierra. It truly does seem to have a shine to it, and Muir was spot-on when calling it the "Range of Light."
The shine on Sierra rocks may be due to the fact that they are granite. This particular section, Ministry Wall, has a different sheen than the surrounding rocks. It does have a black glaze with holds that are sharp and angular.
Well, Pratt's Crack has been there for millions of years, and I guarantee that it will still be there when you come back for it.
I have a question, how did you recognize it from the other photo that was showing only the upper part of it?