Chalk produce, and thus widely used in the developing world, calcium-based chalk can be made where the crumbling particles are larger and thus produce less dust, and is marketed as "dustless chalk". Colored chalks, pastel chalks, and sidewalk chalk (shaped into larger sticks and often colored), used to draw on sidewalks, streets, and driveways, are primarily made of gypsum. Chalk is a source of quicklime by thermal decomposition, or slaked lime following quenching of quicklime with water. In southeast England, deneholes are a notable example of ancient chalk pits. Such bell pits may also mark the sites of ancient flint mines,
Rock Chalk, Jayhawk preceded by the Kansas alma mater "Crimson and the Blue,” and followed by the fight song, "I'm a Jayhawk.” Since the early 1990's, Kansas fans have been known to do the slow repetition of "Rock chalk... Jay-Hawk... KU" when the Jayhawks are believed to be safely ahead, and victory is guaranteed. Rock Chalk, Jayhawk "Rock Chalk, Jayhawk" (a.k.a. the "Rock Chalk" chant) is a chant used at University of Kansas Jayhawks sporting events. The chant is made up of the phrase "Rock chalk, Jayhawk, KU". The chant was first adopted by the university's science club in 1886. Chemistry professor E.H.S.