Leonard James Spencer, 1911 Encyclopædia Britannica, Volume 16… (1911)
“ LEADHILLITE, a rare mineral consisting of basic lead sulphato-carbonate, Pb4SO4 (CO3) 2 (OH) 2. Crystals have usually the form of six-sided plates (fig. 1) or sometimes of acute rhombohedra (fig. 2) ; they have a perfect basal cleavage (parallel to P in fig. 1) on which the lustre is strongly pearly; they are usually white and translucent. ”
