Natural diamonds

Nuclear techniques for the determination of 39 trace elements in diamond are described. These include charged-particle activation analysis and instrumental methods of neutron activation analysis. The selection and preparation of natural diamonds, the determination of hydrogen, boron, nitrogen, and oxygen in diamond, and the instrumental neutron activation of diamond are discussed in detail. A common impurity chemistry found for different diamonds is considered to reflect the composition of the magma from which they crystallised. A relatively succesful attempt was made to differentiate between diamonds from three different kimberlites by the application of discriminant analysis. (T.G.)