Preparation of lightweight aggregate from a sample of Tapleys Hill shale, as successfully achieved by 'bloating' (the expansion of a viscous melt of crushed rock particles by trapped gas released during fusion in a rotary kiln), is described. Six test cylinders of lightweight concrete, containing 7 bags of cement per cubic yard of mix material, were prepared from the aggregate so produced. In subsequent physical testing of these cylinders in a load cell rig, it was found that, at a concrete mix water:cement ratio of 0. 57, they had a bulk density of 88 lb per cu ft and a compressive strength of 2170 lb per square inch. This quality of lightweight concrete would be suitable for load-bearing walls and concrete masonry units such as are used in house construction, and its use would result in a weight saving of about 40%. It would not, however, have sufficient strength for use in structural concrete. Before commercial exploitation of the subject shale deposit can be recommended, further work is necessary to determine means of preventing the tendency of this material to agglomerate in the rotary kiln during expansion, and a recommendation is made to this end.