Cu-acetate (Dark, almost black), Cu-sulphate(blue), ...
Description: Cu-acetate (Dark, almost black), Cu-sulphate(blue), Na-acetate(no color) Home-grown Cu-acetate crystals up to 1cm. Just a home experiment. Dissolved soda in acetic acid -> Na-acetate. Added Cu-sulphate. Some Cu-acetate crystals formed. Still cheaper to buy pure Cu-acetate in the shop.