Blue crystals, obtained when ammonium chloride NH4Cl is crystallized together with copper(II) chloride CuCl2.
- Crystal shape: distorted rhombododecahedrons, octahedrons
- Color: greenish-blue, teal. Less blue than copper sulfate
- Stability on air: stable
To prepare ammonium tetrachlorocuprate, dissolve ammonium and copper chlorides in water, in 2:1 molar ration, then crystallize the solution. Reaction equation is:
2NH4Cl + CuCl2 = (NH4)2[CuCl4]
All copper compounds are moderately toxic.