The golden ratio is a 1 dimensional ratio. You're jumping from one dimension to three dimensions.
In one dimension, two amounts are in the golden ratio if the ratio of the smaller to the larger is the same as the larger to the sum.
Or rather, I would be better to reverse that - the larger to the smaller and the sum to the larger. Either statement holds, but the value of the golden ratio is the larger to the smaller, not the reciprocal.
Now, as several people have noticed, this ONE dimensional concept can be applied to 2 dimensional objects. i.e. examples of the golden ratio in rectangles where the length divided by the width is the golden ratio. I see no problem extending it to the 3rd or greater dimensions, although at first thought, you don't have such simple examples as "take a square out of a golden rectangle, you're left with another golden rectangle."
However, consider the regular pentagon & how the golden ratio can be represented by the intersections of line segments within. Thus, while all regular pentagons are the same "fixed shape", the golden ratio is present by looking at a ratio of line segments within. So, I suppose that a pentagonal prism could be created such that the height of the prism was the shorter length of the intersection of a pair of segments inside the pentagon. Or, hurting my brain a little more, if three golden rectangles are intersected in three dimensions, one along each plane, centered at the origin, the 12 corners form the centers of a dodecahedron. <brain hurting> there's gotta be something you can do with a dodecahedron to create a smaller dodecahedron in 3-D that demonstrates the golden ratio. (i.e. remove a cube from the center & collapse it in on itself? Something along those lines.)