I have not heard any reference to a fluorescent-like glow in any of the Hudson presentations I have encountered. These elements have the characteristics similar to that of porcelain in that they do not chemically react with anything and are very tough, durable, and heat resistant. A powder cannot be described as tough. The glass form, according to Hudson, is very brittle and unlike what we think of as ceramic in terms of hardness. What I would say is that these monoatomic forms are very stable.
Normal nuclei are spherical in shape.
They are held in this shape by the competing forces of all the neighboring atoms of a lattice network. Monatomic elements, on the other hand, have no neighbors to keep them out of trouble. Because the valence band of electrons are only half filled, these heavy elements are inherently physically unstable in the monatomic state. Their perceived instability in high energy physics experiments is probably an artifact of the high energies involved rather than anything which would be noticed under normal earth surface conditions. But, when a monatomic atom starts to vibrate, it tends to be deformed into the elongated shape of a bowlng pin.