CHEMISTRY WITH IGUANA
Some coins (5-10), 1 straw, 1 jar / cup, some ammonia (found in things like bathroom cleaners, you don't need to extract it but the more it has in the better), baking soda, some bleach and salt.
Step 1: put 2 tablespoons of salt and 1 tablespoon of baking soda into the jar
Step 2: Pour the ammonia 2/3 the way full into the jar.
Step 3: Pour bleach the rest of the way up
Step 4: Put the coins into the jar
Step 5: Grab your straw quickly and start to blow directly onto the coins
Step 6: profit!
You should see the crystals start to form up after a few minutes or so of blowing, if you stop however the crystals stop forming. It'll take about 5 to 10 mins to actually start the crystals forming (depending on how much you've been blowing) and then after they've started growing it happens pretty quickly.
Use food dyes for different colours, it'll come out with a glass like finish which is good to sand down and polish, or just keep a cool crystal. The inside is hard as rock but the outside is a bit more brittle.
