Searlesite was discovered in Miyang depression of Henan Province in 1987. It occurs in oil shale of Tertiary alkali-bearing rocks, and its discovery fills a gap in mineralogy of China. Its molecular formula is NaBSi2O5(OH)2, and its crystals show the following features: assuming spherical and bunchy aggregates; colorless; biaxial negative; Ng=1.5345, Nm=1.532 and Np=1.512. Searlesite is of some significance in explaining the depositional environment and material sources of the alkaline deposit in which it occurs.