Nickel carbonate, denoted by the formula NiCO3, is a compound found in various forms, including the green mineral otavite, which is relatively rare in nature. This compound plays crucial roles in nickel plating, serving as a catalyst in organic synthesis, and contributing to pigment production.

Physically, this substance typically presents itself as a light green crystalline solid. It demonstrates insolubility in water but exhibits solubility in acids, such as hydrochloric acid, producing a green solution. Upon heating, it undergoes decomposition to yield nickel oxide (NiO), carbon dioxide (CO2), and oxygen (O2).

Chemically, it displays typical traits of transition metal carbonates. It participates in various reactions including decomposition, reduction, and complexation. In the presence of acids, it liberates carbon dioxide gas, leading to the formation of soluble nickel salts. Although stable under normal conditions, nickel carbonate may slowly decompose in moist air due to its reaction with carbon dioxide.

Given its toxicity, it poses health hazards upon ingestion or inhalation, necessitating careful handling in well-ventilated areas. Proper disposal adhering to regulatory guidelines is imperative. In essence, it with its distinctive physical and chemical attributes, serves diverse applications, ranging from its plating to catalysis, albeit demanding meticulous safety measures.