Actually if radiation is aligned with a crystal lattice it interacts even more with the material and the radiation length (the distance travelled before 1/e of the particles interact on average) gets shorter. However this only happens if the radiation is aligned to within a few milli-radians of the symmetry axis of the crystal (and most metal you encounter is not a single crystal). I actually measured this effect as part of my PhD thesis for an application in the main particle physics experiment I was working on.
So no, this material will probably be no more effective than the same mass of gold in a thin, but solid, sheet. Radiation shielding with matter is a statistical affair and the fewer nuclei you have the less shielding you get. I'm also surprised that they suggest a use in jewelry since they also describe it as easily malleable, far more so than solid gold. Still it is interesting.