Yeah, the cause is similar to "silly putty" it has to do with how the molocules are aligned, especially under stress.
Under stress, silly putty's molocules align at right angles to the stress, so a sharp pull, results in a clean, almost sliced surface.. (where as gentle pressure cause it to stretch.)
dropping hot liquid glass into water, causes a sharp cooling effect, which lines up stress in the glass..
depending on your utility service you might be able to do it over a kitchen stove..
Starting in the 1950's Con Ed added water vapor to the natural gas, so you get few BTU out of a given volume. (you used be be able to melt lead, for plumbing work over the stove!) now you need to use a butane torch.
an other cool liquid, is a suspention of corn starch.. add enough corn starch to about two cups of water (about 1 cup) to make a fluid about as thick as cream.
pour into a pie pan, or some other flat shallow dish.
Rapidly, and hard, smack the fluid! No, no splashes! it too, aligns its self under stress. and a hard smack causes the liquid to behave like a solid! leave your hand there for a moment or two, and you can feel it return to liquid state, and you hand will gentle sink in!
