Hi Steve.
Mineral - Clever idea and nicely executed. I'm going to disagree with the comments about moving the front peppercorns, I tend to prefer that the focal point is some way into the image, which the oof peppercorns facilitate.
Whole - Reading through the comments I love that you turned it over once completing it, it certainly works.
d00ds idea about sticking it to a window certainly has some merit too, one for a re-shoot maybe.
Structure - Agree, the gold reflector works in that the added warmth is good. How did the London trip go? I know there were a few issues with trains, but a lot had cleared by 5pm (I certainly had no issues getting home, but the train was diverted a few stops after mine).