Simplify the following text for a Grade 10 native English-speaking person.
Original: Copper ( II ) carbonate ( often called copper carbonate or cupric carbonate ) is a blue-green compound ( chemical formula CuCO3 ) forming part of the verdigris patina that is found on weathered brass , bronze , and copper .
Simplified: Copper ( II ) carbonate , also known as cupric carbonate , is a chemical compound . Its chemical formula is CuCO3 .