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 radius Ionic radius Ionic radius, "r", is the radius of an atom's ion in ionic crystals structure. Although neither atoms nor ions have sharp boundaries, they are sometimes treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice. Ionic radii are typically given in units of either picometers (pm) or angstroms (Å), with 1 Å = 100 pm. Typical values range from 30 pm (0.3 Å) to over 200 pm (2 Å). The concept can be extended to solvated ions