lucullite

— He next characterized the different British limestones, with reference to the qualities peculiar to each, in the composition of mortars and cements, dividing them into the soft white limestones, such as chalk and oolite, the grey limestones, the bituminous limestones or lucullites, the magnesian limestones, and lastly those fitted for water cements, such as the grey chalk of Dorking, and the blue limestone of Aberthaw and Barrow, and the septaria of the London clay from which Roman cement is prepared, exhibiting specimens of each kind.