“Artificial Rock #119”, by Chinese artist Zhan Wang, is installed in front of the Armory Show booth of Haines Gallery, from San Francisco. (The blue-and-white vases behind it are by Ai Weiwei.) To make the pieces in this series, Zhan takes real “scholars’ rocks”—water-worn stones long used for contemplation among China’s philosopher-aesthetes—and meticulously taps stainless-steel sheets across their surfaces, recording every ridge and cranny. Then those smaller sheets are welded and polished into a full-scale facsimile of the original stone. The reflections that play across Zhan’s “Artifical Rock” are so evanescent that the piece pretty much defeats slow contemplation—all your eyes can do is chase after each new image that skitters across it. The work also dwells on the bauble side of even the most sober collectibles, and acts as a kind of stand-in for all the other precious artworks in the Armory fair.