碳酸铜是一种蓝绿色的铜盐，化学式为CuCO₃。目前尚未制出纯净的碳酸铜，只合成了Cu(en)₂CO₃·2H₂O和Cu(NH₃)₂CO₃等配合物。

亮绿色孔雀石（CuCO₃·Cu(OH)₂）和蓝色石青（Cu₃(CO₃)₂(OH)₂）是天然存在的两种碱式碳酸铜。

氢氧化铜溶于碳酸钾溶液生成深蓝色配位离子溶液。铜盐溶液与过量碳酸钾生成K₂[Cu(CO₃)₂]（暗蓝色）、K₂[Cu(CO₃)₂]·2H₂O（亮蓝色）与K₂[Cu(CO₃)₂]·4H₂O（浅蓝绿色）。

也有认为铜在潮湿空气中生成的铜锈是1:1的Cu(OH)₂、CuCO₃混合物，且碳酸铜加热分解为二氧化碳和氧化铜：

Basic copper carbonate normally refers to the compound (Cu₂(OH)₂CO₃) (the mineral malachite). Sometimes the name is used for Cu₃(OH)₂(CO₃)₂ (the related mineral azurite). Malachite and azurite can be found in the verdigris patina that is found on weathered brass, bronze, and copper. The composition of the patina can vary, in a maritime environment depending on the environment a basic chloride may be present, in an urban environment basic sulfates may be present.