Ionic order cap is usually enriched with egg-and-dart. Since Vitruvius, a female character has been ascribed to the Ionic (in contrast to the masculine Doric). The major features of the Ionic order are the volutes of its capital, which have been the subject of much theoretical and practical discourse, based on a brief and obscure passage in Vitruvius. The only tools required to design these features were a straight-edge, a right angle, string (to establish half-lengths) and a compass. Below the volutes, the Ionic column may have a wide collar or banding separating the capital from the fluted shaft (as in, for
Ionic compound usually in a crystalline structure. Ionic compounds containing hydrogen ions (H) are classified as acids, and those containing basic ions hydroxide (OH) or oxide (O) are classified as bases. Ionic compounds without these ions are also known as salts and can be formed by acid–base reactions. Ionic compounds can also be produced from their constituent ions by evaporation of their solvent, precipitation, freezing, a solid-state reaction, or the electron transfer reaction of reactive metals with reactive non-metals, such as halogen gases. Ionic compounds typically have high melting and boiling points, and are hard and brittle. As solids they are almost