Cobalt(II) carbonate Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids: Cobalt carbonate is a precursor to cobalt carbonyl and various cobalt salts. It is a component of dietary supplements since cobalt is an essential element. It is a precursor to blue pottery glazes, famously in the case of Delftware. The moderately rare spherocobaltite is the natural form of cobalt carbonate, with good specimens coming especially from the Republic of Congo. "Cobaltocalcite" is a name used for a cobaltiferous calcite variety that is quite similar in habit to spherocobaltite. The compound is harmful
Chemical element For example, the formula for heavy water may be written DO instead of HO. Only about 4% of the total mass of the universe is made of atoms or ions, and thus represented by chemical elements. This fraction is about 15% of the total matter, with the remainder of the matter (85%) being dark matter. The nature of dark matter is unknown, but it is not composed of atoms of chemical elements because it contains no protons, neutrons, or electrons. (The remaining non-matter part of the mass of the universe is composed of the even more mysterious dark energy). The