When Lily is handling the Chinese note in the shop, the close up shows hands with bright red nail varnish but in fact Lily isn't wearing nail varnish at all.
After finding the Kwan Yin, and bringing it home to analysis it, the boys are handling the statue. While they turn it over, flip it around, and observe the writing on the bottom, the statue changes in quality.
It changes from a deep, translucent emerald stone, to a lighter shade, but more opaque, almost plastic figure.