When I was a kid, there were this thing I had that involved filling up a mayonnaise jar with water and putting these crystal things in and the crystals would grow into little columns. I think you had to add something to the water to cause the crystals to form or grow, but I have no idea what. They were different colors. Mine never got more than about an inch tall because it was in the garage and one of the neighbor kids knocked it off the dryer and broke it.
Anyone have any idea what this was? And if I can still get it? I think my kids would enjoy it.
We also made some in a shallow dish with charcoal briquets, ammonia, rock salt, and a dashes of bluing and food coloring, IIRC. This yielded some modest, low-lying crystal growths with a bit of color, but nothing spectacular. (Destructive vibrations disrupting the crystals were a problem, though.) And what with the ammonia, it was really smelly.
I’ve wondered if stalactites could be grown with Magic Rocks by gluing the rocks to the lid of a jar. I suppose not, reading the description of how they work.
Maybe growing them upright on a lid in a larger jar, then growing more stalagtites in the smaller jar, with the lid already holding the previous magic rocks…
