In this, the first of two articles on diamond, a review is given of its hardness, its sources, its fabrication and of many of its uses as a technological material. Some examples of etched diamond surfaces, growth features, surface polish and percussion marks are illustrated. The history of man-made diamonds is briefly reviewed. In part 2, which will follow later, aspects to be treated will include absorption spectra, semi-conductivity, diamond counters and irradiation defects.