U+29B5 "⦵" Circle with Horizontal Bar Unicode Character

U+29B5 "⦵" Circle with Horizontal Bar is a mathematical symbol primarily used in chemistry and thermodynamics to denote a standard state or standard conditions, such as for standard enthalpy or standard Gibbs free energy. It appears as a circle bisected by a horizontal line, distinguishing it from similar symbols like the empty set or the degree sign. This character falls within the Miscellaneous Mathematical Symbols-B block and is often employed in scientific notation to specify baseline values for reactions under defined pressures and temperatures.