Further work on two types of diamond

Abstract

In the paper "Two Types of Diamond" many physical properties of diamond are described, and on p. 516 are collected features of difference and of similarity between the two types. Briefly, the ordinary type (Type 1) is characterized by greater apparent homogeneity, Type 2 having a mosaic structure but greater isotropy in polarized light; in infra-red absorption Type 1 has a strong band at 8 μ, this being absent in Type 2; in the ultra-violet Type 1 absorbs up to a point much nearer the visible region than Type 2 which is transparent nearly as far out as quartz; Type 1 has little, Type 2 a marked photo-conductivity; while the X-ray pattern exhibits slight differences interpreted as supporting the greater degree of mosaicness of Type 2. The two types were similar in respect of the electron diffraction, the Raman spectrum, tribo-luminescence, dielectric constant, refractive index, specific gravity, and colour.