CuSO4 (Copper sulfate) is a chemical can everyone buy in almost every drugstore or on the internet. I bought like 1 kg, it is quite cheap, but you dont need so much.. Buy it in powder form.
Growing crystals from CuSO4 is well known thing. I've made many of them and i was thinking how if would look like if i try to grow them on an ordinary rock. And here it is...beauty:*
Procedure is very simple and it is reversible process....
!!! This chemical is toxic !!! Wear protection !!!
!!! Don't breathe it, touch it too much and certainly don't eat it no matter how tasty it looks !!!