Blackboard ‘chalk’ are produced especially for use with blackboards in white and also in various colours. White chalk sticks are made mainly from calcium carbonate derived from mineral chalk rock or limestone, while colored or pastel chalks are made from calcium sulfate in its dihydrate form, CaSO·2HO, derived from gypsum. Chalk sticks containing calcium carbonate typically contain 40–60% of CaCO (calcite). As compared to whiteboards, blackboards still have a variety of advantages: On the other hand, chalk produces dust, the amount depending on the quality of chalk used. Some people find this uncomfortable or may be allergic to it, and according
What Are Little Boys Made Of? appear in several popular songs, including "Nothing Can Change This Love" by Sam Cooke from 1962 and "Sugar and Spice" by The Searchers, from 1963. "Sugar and spice, and all things nice" is also a verse in the Stone Roses early single "Sally Cinnamon". Van Halen in 1991 released the song "Poundcake," which contains part of the lyrics in the beginning of the music video. Alternative rock band Garbage incorporate the words of the rhyme in their song, "What Girls Are Made of," on the Deluxe edition of their 2012 studio album "Not your Kind of People". In October, 1966,