From Online Dictionary of Crystallography
Revision as of 17:15, 9 November 2017 by BrianMcMahon (Tidied translations and added German and Spanish (U. Mueller))
Plan d'accollement, surface d'accollement (Fr). Verwachsungsebene (Ge). Piano di composizione, superficie di composizione (It). 接触面 (Ja). Plano de composición (Sp).
The surface that separates two individuals (domains) in a twin is called composition surface or, when it has the regular shape of a plane, composition plane. The former is characteristic of penetration twins, the latter of contact twins.