Why salt crystals grow as pyramids (sometimes)

Some explanations are so remarkably simply that I never would've thought of them.

I've heard of hopper crystals in bismuth for years. I always assumed that they were studied by a scientist named Hopper. In this video, Adam Ragusea explains that they're actually called hopper crystals (not Hopper crystals) because they resemble the shape of a hopper that feeds ingredients into a production line.

And that's just the surface level of new knowledge that I got from this video. Adam spends much more time trying to explain why making hopper crystals of salt - the ones he shows and that I have in my cabinets at home as Maldon salt - is hard to do. Apparently they only form in super-saturated salt solutions and then only stay hopper-shaped pyramids until they either bump into other crystals to form a raft or get heavy enough to sink to the bottom of the solution and in-fill with more salt.

If only they could get them to grow in space - as an International Space Station experiment shown in the video recounts...