Surface Markings on a Diamond

Abstract

ACCORDING to the mosaic hypothesis, it is postulated that the uniform lattice structure of an ideal crystal is interrupted over narrow regions distributed periodically throughout the crystal at distances large compared with the size of the unit cell. Various forms of the hypothesis have been devised to explain anomalies in the intensity of reflection of X-rays, breaking strength and other structure-sensitive properties of crystals, but the subject is at present highly controversial. Whilst many facts undoubtedly fit the hypothesis, several workers claim that some half dozen other types of fact do not fit¹. All forms of the hypothesis including the lineage structure proposed by Buerger² would predict non-uniformity on such a section of a crystal as a crystal face. Hence all observations of small-scale regular markings such as etch figures and slip bands at the crystal surface and especially their minimum dimensions are highly relevant to the subject.