Cupri Sulfas – good old days
I bought 250g at the pharmacy and boiled up water. After boiling it I poured the water and some of the copper sulfate in a bowl while stiring. As much as I could as long as it disolved. Then I waited for a few days and it turned into wonderful crystals. Like these ones:
I haven’t made any for a while so I had to find a photo on Wiki – maybe I should try this again soon.