Metchosin

As a kid, we used to be able to grow the 'coral' from kits of 'rocks'. I also remember having a very special 'chemistry for kids' book, one item in which was how to do that from scratch, including crystals such as copper sulphate.

Don't remember the ammonia, but I do remember sodium silicate - water glass.

Most of the chemicals were readily available from a hardware store, or occasionally a chemist, but these days you'd probably find yourself in Gitmo if you even asked for them...