For jewelry purposes, jet should be opaque, pure black in color, faultless, and homogeneous throughout. The good surface polish which it takes is soon scratched in wear, and the material is easily cracked, chipped, or broken. Yet good examples of old jet jewelry,; some of which is carved, still exist, but its sale is very limited. The chief English source of supply is the Yorkshire coast, near Whitby and Eskdale. Here, it is still worked by a few people, although once some three thousand hands were employed in this industry. It is recorded that there were about 1,400 jel workers in Whitby alone in the year 1870, but at that time, mate rial was also imported from abroad and worked.