Okay, so this is easy, you should have all of the chemicals needed around the house!
Youll need around 5-8 pennies (or copper coin from your country), and a straw, put these aside.
Get a clear jar, scoop 2 tablespoons of salt into it, and 1 tablespoon of baking soda.
Now the first important ingredient should be in the bathroom cleaning supplies: Ammonia (any brand). Pour it in until the jar is 2/3 of the way full (as tall as you want the crystals to grow)
The last ingredient is laundry bleach (careful not to spill on your clothes!), fill the rest of the jar.
Now drop the pennies into the bottom, and quickly take the straw and blow bubbles onto the pennies to get the crystals going. You should begin to see stringy crystals form after about 30 seconds of blowing. That’s it!
The attached pic took around 10 minutes of steady blowing
The pink and purple some from the production of copper-calciphate using the CO2 in your own breath! (blowing until youre dizzy actually increases the CO2 in your breath, giving better colors)