Note: I have provided links at the end of the answer on how to grow the various crystals that I've mentioned as well as on how to make jewellery with these homegrown crystals. read more
Monoammonium phosphate salt can be used to grow green crystals that look kind of like emeralds. The salt used may not be too safe though as it can cause skin irritation in some people. Colourless crystals can be grown from substances like Epsom salt and borax too. read more
You can check in on it and you will see crystals start to grown after the first day or two! 3. Once you see a good amount of crystals that have grown, you can move forward. read more
Other common household items can also be used for crystal making. Check out this quick crystal project using Epsom salts (magnesium sulfate) . Or use alum powder used for pickling (spices section of grocery store). Check out some tips on alum crystal growing here. read more